Comment 12 for bug 604777

I have the same problem on eeePC 1005PE after updating to ubuntu 10.10. Use of RAM ~20% while system runs out of swap and mutter dies in pain. All you need is to roll with a mouse over sidebar on left (quicklists). System is totally unusable, however looks like unity 2D version does not have this problem.

video card:
00:02.0 VGA compatible controller: Intel Corporation N10 Family Integrated Graphics Controller (prog-if 00 [VGA controller])

mutter errors while you are just rolling over icons on a quicklist bar (see attachment for a full mutter log) :

(mutter:3660): libunity-private-WARNING **: quicklist-controller.vala:165: state change called on menu when menu does not exist

(mutter:3660): Clutter-WARNING **: The actor 'UnityLauncherQuicklistMenu' is currently inside an allocation cycle; calling clutter_actor_queue_relayout() is not recommended