i upgraded a 1.0.2 - 1.1.1... The person took the phone and hooked up to their PC and tried syncing it and got their pda info to sync but when it came to their music theyre getting this error:

"THE IPHONE CANNOT BE SYNCED: THE DISC COULDNT BE READ FROM OR WRITTEN TO"

They get 300 out of 600 of their songs onto their phone...... I took the phone and used swap tunes and swapped libraries and connected the phone to my mac and loaded 800+ songs on to it with no problem... they then took the phone back home and swapped libraries back over and tried to sync and got the same errors.... both computers are running itunes 7.5.... Has anybody else come across this problem??