ipod/music problem
1. back up before you do anything with your current iTunes b6 if using IOS5 B6
2. run OTA ios5 b7 allow at least 30 minutes and install iTunes 10.5 b7 (simultaneously if you want)
3. once install complete in iTunes with iPhone connected uncheck both music and photos and click apply ,this will remove all music,video,photos content.
4.check your iPhone iPod app to make sure no music or playlist are there !!
5.simply go back to iTunes with iPhone connected goto Music tab and click check for sync music and goto photos tab and do the same .
6. bottom line is before doing all this you should follow the erase all content note in the release notes and re-sync avoids the problem.
my first post here ,been watching for years .
for the trolls/miserable gits that lurk here quoting its beta wait till it releases officially,this is a non constructive answer , I am a registered developer and have accounts for many developer beta projects ,i come here to see what problems many experience and use that info whether its right or wrong I often come across issues that don't appear elsewhere .
have a nice day and if it helps it did some good if it didn't help then it goes deeper and needs more constructive solutions .
brian