Is it possible that 0.7.1a is running on a different graphics card/in compatibility mode/something else along those lines?
Another thing to try: renaming the jre folder in the 0.7.2a directory, and copying over the jre folder from 0.7.1a.
But - thinking about this some more, I now remember changing something about the rendering code that has to do with this. The thing is, it was a simple change and I'm fairly confident in the code being "correct", and it does appear to work in the general case. This seems to point to this potentially being a driver issue; can you check to see if your graphics drivers up-to-date? If so, what the model of the card is would be good to know for reference, as well.
(Edit: I can't just revert the change, unfortunately, as it was needed to make something else work. Might be able to work around it, though if it *is* a driver issue, that's kind of a minefield, without knowing beforehand what will and won't work, and not being able to test it.)
