diff --git a/src/system/kernel/cache/block_allocator.cpp b/src/system/kernel/cache/block_allocator.cpp
index 17da1330df..9444b45ce4 100644
--- a/src/system/kernel/cache/block_allocator.cpp
+++ b/src/system/kernel/cache/block_allocator.cpp
@@ -9,7 +9,6 @@
 #include <KernelExport.h>
 
 #include <util/AutoLock.h>
-//#include <vm.h>
 #include <vm_address_space.h>
 #include <vm_page.h>
 
diff --git a/src/system/kernel/cache/block_cache.cpp b/src/system/kernel/cache/block_cache.cpp
index 1b2df13ebe..62e53139aa 100644
--- a/src/system/kernel/cache/block_cache.cpp
+++ b/src/system/kernel/cache/block_cache.cpp
@@ -264,8 +264,9 @@ block_cache::FreeBlock(cached_block *block)
 	ASSERT(range != NULL);
 	range->Free(this, block);
 
-	Free(block->original);
-	Free(block->parent_data);
+	if (block->original != NULL || block->parent_data != NULL)
+		panic("block_cache::FreeBlock(): %p, %p\n", block->original, block->parent_data);
+
 #ifdef DEBUG_CHANGED
 	Free(block->compare);
 #endif
@@ -804,8 +805,9 @@ cache_abort_transaction(void *_cache, int32 id)
 			cache->Free(block->original);
 			block->original = NULL;
 		}
-		if (transaction->has_sub_transaction && block->parent_data != block->data) {
-			cache->Free(block->parent_data);
+		if (transaction->has_sub_transaction) {
+			if (block->parent_data != block->data)
+				cache->Free(block->parent_data);
 			block->parent_data = NULL;
 		}