Excellent observations. And the fact that the file pointer doesn't automatically reset to the top of the file on each iteration is something that I periodically get hammered by, too.

I think I would not have bothered with regexs at all. In the OP's posting, the lines from File 1 are already split and it would be trivial to do the same with File 2. I would think it would be clearer and more straightforward to do both splits and then do a simple logical compare on the name-parts.

The regex's, of course, will work (especially given some of the other suggestions from responders to the OP's post); but it seems like the logical compares would be more readable and maintainable, IMHO. But that's just my perspective.