diff -ur linux-2.4.19/drivers/block/DAC960.c patched-2.4.19/drivers/block/DAC960.c
--- linux-2.4.19/drivers/block/DAC960.c	2002-09-13 17:41:30.000000000 +0200
+++ patched-2.4.19/drivers/block/DAC960.c	2003-04-16 11:07:16.000000000 +0200
@@ -5398,8 +5398,10 @@
   /*
     Decrement the Logical Drive and Controller Usage Counts.
   */
-  Controller->LogicalDriveUsageCount[LogicalDriveNumber]--;
-  Controller->ControllerUsageCount--;
+  if (Controller->LogicalDriveUsageCount[LogicalDriveNumber] > 0)
+    Controller->LogicalDriveUsageCount[LogicalDriveNumber]--;
+  if (Controller->ControllerUsageCount > 0)
+    Controller->ControllerUsageCount--;
   return 0;
 }