Another tip - if you do the 320 bit rate hack from the post stuck in the Windows Phone 8 thread, make sure before you sync stuff to the card that you go into the card's properties in windows media player and move the dial to 320 again.
I had to delete and resync all over again, and since it was my second time already, I then ran into some issues where only some stuff synced and other songs were missing despite wmp saying they were already on the phone.
luckily, I went back and deleted everything off the card again, restarted phone and PC, and synced again and now everything seems to be working fine.
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