Every alarm application doesnt work with music library iPhone

Are you talking about the stock Clock application? It does not give you the option to set the sound to a playlist.
MacPro Dual Core 2.66 Ghz, MacBook Pro 15", iPhone 4 Mac OS X (10.6.6) AEXs, Red 2G & 5G Nano, Red Shuffle, 160 GB Classic, Apple TV

deggie, I think he said his native Clock alarm works fine (ie, as intended), but 3rd party alarm apps wont play his music.
Il Compare, my first guess is you may be minimizing the app. All the 3rd party alarm apps Ive used require you to leave the app running in the foreground (ie, do not minimize) in order for them to play your iPod music. In most (all?) cases, if the app is minimized, itll only play from its own sounds. For whatever technical reason, they cant play your music while in background mode.
Hope this helps.