Again, no offense, but if you installed something 3 months ago, but only called into play a certain aspect of that program 1 month ago, which then started buggering your system, it would certainly *look* like it was Vista 's fault as you hadn't installed anything new in 1 month - but in point of fact it was something that you did in another application that you had never done before that in fact caused the problem, only at the time it didn't throw up any warnings or alert you to any changes being made.
As you yourself said, it was not a problem OOB, so something in the interim caused the problem.
Now, a good place to start to eliminate problems would be hardware diagnostics as well as running
to see if there is any critical file corruption going on here.