I downloaded a par2 file, and the program got stuck at decoding. I left it along for a long time (still less than 30 minutes) and came back.
I checked the log and it said that the filename was too long. There were quite a few entries for the same file. I also noticed that 99% of my processor was in use, so I opened the task manager and found that alt.binz was using over 400 MB of ram and ~99% of the processor.