iTunes sync with iPhone4 after RAM replaced

My MBP resently had to have the RAM stick replaced and in the process the HD was cleared. Iv slowly gotten things back to simi-normal, but now it seems I cannot sync my iPhone4 with music from iTunes.

Iv tried everything. I have so much music there is no way I can even think of using iCloud and have always done the changes by connecting to the MBP. No matter if I click playlist, artists or albums not everything will sync.

Multiple artists with 2, 3, 4 or more albums ... only 1 of the multiples will sync. Others won't even show up at all ...

Everything else syncs perfectly, but something about music has me totally stopped.

What can I do?