I have just installed 11.10 on my dual monitor system, I have a problem with the panel menus (settings/power, memenu, calendar etc.).
What is happening is on one monitor, everything functions fine, but on the other, the menus do not stay open when I click on them. The will appear briefly, but then close straight away. If I click and hold they stay open, but only until I let go.
Like I said, this only happens on one monitor at a time, but the monitor on which it happens seems to change.
OK it seems there is a bug filed for this here: bug report (thanks Adrian). Still no fix out yet.