diff --git a/manifest b/manifest
index 8411b2239f..81aef14195 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\srace\scondition\sin\sOP_ParseSchema.
-D 2011-04-02T09:44:43
+C Avoid\sreturning\sSQLITE_NOTFOUND\swhen\sthe\sunix\sxSetSystemCall\sinterface\sis\sinvoked\swith\sNULL\spassed\sas\sthe\ssecond\sargument,\seven\sif\sall\sthe\sdefault\ssystem\scalls\sare\salready\sinstalled.
+D 2011-04-02T17:00:48
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 7a4d9524721d40ef9ee26f93f9bd6a51dba106f2
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -162,7 +162,7 @@ F src/os.c 22ac61d06e72a0dac900400147333b07b13d8e1d
 F src/os.h 9dbed8c2b9c1f2f2ebabc09e49829d4777c26bf9
 F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 2596fd2d5d0976c6c0c628d0c3c7c4e7a724f4cf
-F src/os_unix.c a3b4cdf50a9c9be8b50dc4932354ab749962a07f
+F src/os_unix.c 32414676594a0a26cfccd7e02656230a3406eee7
 F src/os_win.c 24d72407a90551969744cf9bcbb1b4c72c5fa845
 F src/pager.c 6aa906b60a59664ba58d3f746164bb010d407ce1
 F src/pager.h 3f8c783de1d4706b40b1ac15b64f5f896bcc78d1
@@ -222,7 +222,7 @@ F src/test_schema.c 8c06ef9ddb240c7a0fcd31bc221a6a2aade58bf0
 F src/test_server.c bbba05c144b5fc4b52ff650a4328027b3fa5fcc6
 F src/test_stat.c f682704b5d1ba8e1d4e7e882a6d7922e2dcf066c
 F src/test_superlock.c 2b97936ca127d13962c3605dbc9a4ef269c424cd
-F src/test_syscall.c 61bb14684142a19c580a13b4dde680044d37e0f5
+F src/test_syscall.c 34ce1be806cd180e241bc688ae3762e5e7825bda
 F src/test_tclvar.c f4dc67d5f780707210d6bb0eb6016a431c04c7fa
 F src/test_thread.c bedd05cad673dba53326f3aa468cc803038896c0
 F src/test_vfs.c 2ed8853c1e51ac6f9ea091f7ce4e0d618bba8b86
@@ -594,7 +594,7 @@ F test/notnull.test cc7c78340328e6112a13c3e311a9ab3127114347
 F test/null.test a8b09b8ed87852742343b33441a9240022108993
 F test/omitunique.test bbb2ec4345d9125d9ee21cd9488d97a163020d5f
 F test/openv2.test af02ed0a9cbc0d2a61b8f35171d4d117e588e4ec
-F test/oserror.test 6c61c859cd94864cfd6af83e0549e2800238c413
+F test/oserror.test 0abf1b4a935aae329b95da27388d7ca61aaea6f0
 F test/pager1.test d8672fd0af5f4f9b99b06283d00f01547809bebe
 F test/pager2.test 745b911dde3d1f24ae0870bd433dfa83d7c658c1
 F test/pager3.test 3856d9c80839be0668efee1b74811b1b7f7fc95f
@@ -677,7 +677,7 @@ F test/subselect.test d24fd8757daf97dafd2e889c73ea4c4272dcf4e4
 F test/substr.test 18f57c4ca8a598805c4d64e304c418734d843c1a
 F test/superlock.test 5d7a4954b0059c903f82c7b67867bc5451a7c082
 F test/sync.test ded6b39d8d8ca3c0c5518516c6371b3316d3e3a3
-F test/syscall.test d1dae1fee88613cf763d97ad0038d867509e0c42
+F test/syscall.test b967e1f5405bb1c9e2e223dbf7d7cd35220589a3
 F test/sysfault.test c79441d88d23696fbec7b147dba98d42a04f523f
 F test/table.test 04ba066432430657712d167ebf28080fe878d305
 F test/tableapi.test 2674633fa95d80da917571ebdd759a14d9819126
@@ -926,7 +926,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 20afd81a4cf4d23962ec841bbd375f36a5156fb6
-R 25d34b3e2efbdd1c8e0ceadec6512306
+P 71a799b02a3b3cf2e12758dea29fd2465bbec3e1
+R 96ca391ad53fdccc5149ee67daf1eb80
 U dan
-Z 659aea6fa897bf521b0a686e5d197299
+Z 09bfa66b6aa34161ab06f7710f843391
diff --git a/manifest.uuid b/manifest.uuid
index fa61c3c651..098e94575a 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-71a799b02a3b3cf2e12758dea29fd2465bbec3e1
\ No newline at end of file
+3b91eaaa0b3c25022332ba3d1a5651848fc5d84c
\ No newline at end of file
diff --git a/src/os_unix.c b/src/os_unix.c
index f04b6af273..67dd06fc1c 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -394,10 +394,10 @@ static int unixSetSystemCall(
     /* If no zName is given, restore all system calls to their default
     ** settings and return NULL
     */
+    rc = SQLITE_OK;
     for(i=0; i<sizeof(aSyscall)/sizeof(aSyscall[0]); i++){
       if( aSyscall[i].pDefault ){
         aSyscall[i].pCurrent = aSyscall[i].pDefault;
-        rc = SQLITE_OK;
       }
     }
   }else{
diff --git a/src/test_syscall.c b/src/test_syscall.c
index a757e66a5a..c570b71e81 100644
--- a/src/test_syscall.c
+++ b/src/test_syscall.c
@@ -599,6 +599,24 @@ static int test_syscall_list(
   return TCL_OK;
 }
 
+static int test_syscall_defaultvfs(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_vfs *pVfs; 
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 2, objv, "");
+    return TCL_ERROR;
+  }
+
+  pVfs = sqlite3_vfs_find(0);
+  Tcl_SetObjResult(interp, Tcl_NewStringObj(pVfs->zName, -1));
+  return TCL_OK;
+}
+
 static int test_syscall(
   void * clientData,
   Tcl_Interp *interp,
@@ -609,13 +627,14 @@ static int test_syscall(
     const char *zName;
     Tcl_ObjCmdProc *xCmd;
   } aCmd[] = {
-    { "fault",     test_syscall_fault },
-    { "install",   test_syscall_install },
-    { "uninstall", test_syscall_uninstall },
-    { "reset",     test_syscall_reset },
-    { "errno",     test_syscall_errno },
-    { "exists",    test_syscall_exists },
-    { "list",      test_syscall_list },
+    { "fault",      test_syscall_fault },
+    { "install",    test_syscall_install },
+    { "uninstall",  test_syscall_uninstall },
+    { "reset",      test_syscall_reset },
+    { "errno",      test_syscall_errno },
+    { "exists",     test_syscall_exists },
+    { "list",       test_syscall_list },
+    { "defaultvfs", test_syscall_defaultvfs },
     { 0, 0 }
   };
   int iCmd;
diff --git a/test/oserror.test b/test/oserror.test
index d1952a30dd..82a5d5f6ff 100644
--- a/test/oserror.test
+++ b/test/oserror.test
@@ -111,6 +111,7 @@ do_test 2.1.3 {
 } {}
   
 
+test_syscall reset
 sqlite3_shutdown
 test_sqlite3_log 
 sqlite3_initialize
diff --git a/test/syscall.test b/test/syscall.test
index 21295a59cf..95921bd35e 100644
--- a/test/syscall.test
+++ b/test/syscall.test
@@ -19,8 +19,12 @@ if {[llength [info commands test_syscall]]==0} {
   finish_test
   return
 } 
-set testprefix syscall
 
+if {[test_syscall defaultvfs] != "unix"} {
+  finish_test
+  return
+}
+set testprefix syscall
 
 #-------------------------------------------------------------------------
 # Tests for the xSetSystemCall method.
@@ -52,12 +56,14 @@ do_test 2.1.2 { test_syscall exists nosuchcall } 0
 #-------------------------------------------------------------------------
 # Tests for the xNextSystemCall method.
 #
-set syscall_list [list                                \
-    open close access getcwd stat fstat ftruncate     \
-    fcntl read pread write pwrite fchmod              \
-]
-if {[test_syscall exists fallocate]} {lappend syscall_list fallocate}
-do_test 3.1 { test_syscall list } $syscall_list
+foreach s {
+    open close access getcwd stat fstat ftruncate
+    fcntl read pread write pwrite fchmod fallocate
+    pread64 pwrite64
+} {
+  if {[test_syscall exists $s]} {lappend syscall_list $s}
+}
+do_test 3.1 { lsort [test_syscall list] } [lsort $syscall_list]
 
 #-------------------------------------------------------------------------
 # This test verifies that if a call to open() fails and errno is set to
@@ -245,6 +251,5 @@ foreach {tn hint size} {
   } $size
 }
 
-
-
+test_syscall reset
 finish_test