Umm... I found a MIDI file (attached) which crashes Winamp 5.02 when you try to open it...
It was composed on a Sony Ericsson T630 mobile phone and transferred to the PC from there. Windows Media Player displays an error when trying to open it, but the file reportedly *does* open on some MIDI editor (Finale 2003). In any case, it shouldn't crash Winamp... =\
Source:
This forum thread (note: this thread is in the "Testing & Trashing" forum of that board, so it will be pruned sooner or later).