password changed after repairing ipod touch! Can't restore!

My iPod Touch 4G had the common "dead home button", so I sent it to be repaired. When it returned, my password was not the same and I couldn't access anything. When I called the repair shop, they said to do a restore. But, I can't seem to restore the device without knowing the password on the device! It does play music, but the playlist seems to be a version from over a month ago.

Any advice on how to get the device restored, or recovering without knowing. It seems to have reverted to a previous state somehow, and (I'm guessing) the password at that time??? I change the password frequently, so my guessing only lands me in "Apple jail" and my device gets locked for up to 60 minutes!

Is this common, and what can I do to get beyond this? I'm ok restoring it, but how can I do so without knowing what password it expects?