Comment 12 for bug 755099

Something similar happened to me in Ubuntu 12.10. I accidentally pressed Super, getting the dashboard, then pressed it again to close it. After this, keyboard and mouse stopped working. All of the apps continued to run just fine - but I couldn't interact with them.

Xorg.log had this line at the end:
[ 17877.120] [mi] Increasing EQ size to 512 to prevent dropped events.

When I killed compiz, everything started working again.