Comment 6 for bug 964270

Another confirmation on 12.10, using Unity. I did not experience this bug using 12.04.

Interestingly this seems to reset shortcuts where there is a default, but not new ones. In my case, I replace "Shift to workspace right" with Ctrl-Alt-h, rather than Ctrl-Alt-right arrow. (And the rest of the vim direction keys). This shortcut gets reset. But I also have Ctrl-Alt-m set (via CCSM) to move a window to the next display port (multi monitor thing using the compiz Put plugin) as that shortcut survives reboots.

Don't know if that helps narrow it down.