Difficult NDIS panic

A plea for help…

I am debugging an NT4 intermediate NDIS driver.
When running under extremely heavy load for
a long period of time, I am experiencing a
panic in NDIS.

The panic occurs when my intermediate driver
completes an outstanding send by calling
NdisMSendComplete. This is called from
my intermediate driver’s SendComplete
routine.

The NDIS panic is occuring when I apparently
dereference a NULL pointer in a routine
called ndisDeQueueOpenOnProtocol.
Can anyone offer any suggestions on what
I might be doing wrong? The parameters
that I am passing in to NdisMSendComplete
look correct.

The entire stack is:

NT!RtlpBreakWithStatusInstruction
NT!KeBugCheckEx+0x1e7
NT!KiTrap0E+0x284
NDIS!ndisDeQueueOpenOnProtocol+0x1f1
NDIS!ndisMFinishClose+0x37
NDIS!ndisMSendCompleteX+0x191
MyIntermediateSendComplete+0x82
NDIS!NdisMSendComplete+0x20a
MyMiniportXmtDpc+0x212
MyMiniportProcessIntr+0xb4

Thanks for any help/suggestions.

Pete