[fpc-pascal] what is the possible cause of EPrivilege Privileged instruction ?

[Dennis]

I have a multi threaded program which executes a list of tasks in real time.
It is difficult to debug with a debugger on this program (since 
debugging will pause the execution which will be messy for this 
application).

So, I log the exceptions to a log file and I found this exception:
EPrivilege    Privileged instruction

What could possibly raise this exception?

My program is win 32 from Lazarus 1.7  FPC 3.1.1
and running on Win 7 64 bit.

thanks in advance.

Dennis