This sounds like a change in the bluetooth drivers due to your upgrade. I've marked this as a bug in the kernel.
** Changed in: Ubuntu Sourcepackagename: None => linux-source-2.6.15 -- Mouse behaves abnormally when bluetooth connected. https://launchpad.net/bugs/46037 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
