virtualbox.org

[solved] I resolved this by unchecking the USB filters in Settings (they were originally unchecked but I thought they were necessary for full USB functionality in the guest; apparently not so).

The mouse was working fine in VB 3 (Linux Mint host, WinXP Pro guest), but now it freezes. This is an external USB mouse. The Synaptic track pad still works fine (ThinkPad T43). Any ideas? Oh, and I'm unable to return the mouse to the host with right-Control.

What is the host?
I resolved all mouse problems by moving the mouse to a PS2 port myself.
Scroll and mouse movement was sporadic at best when in the USB port. Now it is flawless.

The host is Linux Mint 7 (Ubuntu 9.04). I "solved" the problem by plugging the mouse into a USB port on the ThinkPad T43 instead of a USB hub. Duct-tape solution, but maybe it'll work.