.mp3, id3v2 every audio file I put there. Works right on my N95 (checked) and on my iPod Touch (checked). Some of the files it just scanned like half, there is artist name, but not album, title or track number for example (or no artist name or title, but album title is there).

Edit. it seems that I was too happy about earlier: changing id3v2 tags to v2.4 only helped three albums. it still wont scan about 10 albums which both ipod touch and n95 can scan correctly. holy hell this media player was worser than I remembered