Thanks for your replies Tom and Ed. The knowledgebase article was very useful.
There are multiple threads in my program that read the analog inputs. However, I'm protecting
access to the analog card with the mutex locks provided by LabWindows/CVI. The really
puzzling thing is that the software and the hardware have been working fine for over 3 months
and with no changes to either of them, this issue is starting to show up. Maybe the problem was
there all along and is only showing up now because additional (unrelated) software was installed
on the PC which might have changed the timing of the threads. I will investigate further.
Thanks for your help.
Chandan