The unit has been working fine for several months, and last night, my volume froze up. The volume control buttons on the Z1 don't do anything at all, the volume is completely frozen at the level I had it set at. Volume will not adjust up or down at all. Good thing it wasn't really loud. I've done the firmware update, BT update and Gracenote update with no issues at all. The unit is not bypassed at all, it's set up the way Pioneer intended for it to be. My Z1 was manufactured in March of 2006.

Any ideas as to why this is happening? Suggestions?

If u use a remote, are u able to change the volume level?

Don't use a remote. I do have the SWI-PS connected, but the volume doesn't work with that either. All other functions work normally, just can't turn the volume up or down. Sometimes it cuts in and out. I forgot about that earlier. The vol. will go back to normal for a few seconds, then it freezes and again.