Right. Interesting.

I inserted a VCD (made with Nero, ran fine on my other PC in both WMP and Intervideo WinDVD)

It plays in WMP fine, but same problem when trying to play in Intervideo WinDVD... Get error pop up saying it has to close.

So I am ginna uninstall WinDVD and try a different one I have - see if that works.