I had the same problem with CentOS 4.4 running on Dimension E521. However upon replacing the Dell mouse with a Logitech Click Optical Mouse, the problem went away.
-Michael -- Mouse pointer freezes in Dell Dimension E521 / nForce 430 https://launchpad.net/bugs/67734 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
