Hi, Christian.
>Can anyone suggest a good, inexpensive regression testing software application that works well with VFP 9?
I don't know very well what do you mean by "regression testing software", but if it is a unit testing framework, you can get FoxUnit for free at:
http://www.foxunit.org/Although it has been no new versions in a couple years, it is pretty stable. It has a few things but you can workaround them or fix them. All the source code is provided and it is very short code, indeed.
Of course, to catch regression errors, you'll have to write a good set of tests, but this is the only way to do it. I really don't recommend using tools that automatically generate unit tests, because they provide no real value. Unit tests should be manually written because they should prove the business logic is right.
Hope this helps,