The file renamer now replaces "invalid" characters ('?', '*', "/", ...) with an underscore. This should make it more usable. There is still an issue regarding ":", which is invalid on some file systems and actually used on others. For now ":" is hardcoded to be invalid only on Windows, but that's not quite OK, because people mount in one OS file systems from another.
Also, the file renamer now works on Windows too.
Other changes in 0.99.02.020:
1) A fix for an assertion failure that was triggered by badly broken files.
2) Duration is now shown for audio streams.
3) More system information details in the assert dialog
4) Added a system information tab to "about" dialog
If you download the source, make sure you get the right one. SourceForge seems broken, and I can't find a way to make it use 0.99.02.020 for the default download (instead it points to 0.99.02.018)