ZwTerminateProcess() generates exception on Vista?

NTDEV
1

I have algorithm successfully working on 2K/XP.
But it generates exception on Vista.

Really algorithm terminates process and ZwTerminateProcess() generates exception with reason APC disable count is non-zero (0x000ffff) which means bad contest for calling.

What is reason for difference of working on XP and Vista?
How it may be fixed?

Thanks,
MichaelG.