BSOD with IRP_MULTIPLE_REQUEST [NT 4 SP6]

Hello !

What means a BSOD with a BSOD with IRP_MULTIPLE_REQUEST message ?
And second question (maybe linked to the first): Can I set a cancel
routine for an IRP created by the I/O manager and then call IoCancelIrp()
in the IRP_MJ_CLOSE dispatch routine (my IRP is not queued in any queue) ?
If I cannot set a cancel routine or call IoCancelIrp(), how does the IRP
is cancelled when CloseHandle() is called ?

Thanks for your answers