Given that you are on a beta version of iOS, the App is unsupported.
Rekordbox app and iOS 6
I've installed the new rekordbox app on my iPhone 4S and iPad 3 running iOS 6 beta 4. I have imported my music file from the rekordbox app on my macbook (ver. 1.6.2). When i tap on prepare all my tracks and information are displayed on the handeld but the playback function doesn't work nor cue or hotcue buttons. The waveform aren't displayed and all the track has 95:12:34 lenght (see attached photo). I've tryed to reanalyze the tracks but it didn't work.
That means that in 1/2 month (when will be officially released iOS6) will be released a new version of the app with full compatibility?
No, just as previous iOS updates left some apps unsupported as their developers had not yet released versions 100% compatible with the newest version of the platform. When you see an update stating compatibility, then Pioneer has tested it and it should work. Any crashes or errors at that time will be supported.