http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ddtools/hh/ddtools/bccodes_6vxj.asp
SUMMARY
=======
This article describes how to use a sample debugging session to determine
which specific driver is causing the following error message:
Stop Error IRQL_NOT_LESS_OR_EQUAL (0xA)
SYMPTOMS
========
After you install a driver, the system stops responding and you receive the
following error message in nt!KiActivateWaiterQueue+0x27:
Stop Error IRQL_NOT_LESS_OR_EQUAL (0xA)
The initial stack trace indicates that the problem is in the Fast Fat
driver.
CAUSE
=====
This problem typically occurs because drivers call either the
IoQueueWorkItem() function or the ExQueueWorkItem() function two times on
the same work item before the work item has been executed.
Device drivers that statically allocate either the IO_WORKITEM structure or
the WORK_QUEUE_ITEM structure are particularly prone to this problem. Device
drivers that perform such a static allocation must guarantee that they do
not try to use the statically allocated item while it is already queued.