I had the BPM for a song set to around 246 (the offset was at 16 seconds, I think) and when I clicked on the Timing Setup Panel, it reset everything (removed the timing, offset, song name, song creator, etc.). It seems like a fairly minor bug, because I was able to restart osu! and continue editing the song, (although the settings were still at default) but It's probably good to report it anyway.