This bug has been copied from bug #482990 and has been proposed
to be backported to 5.3 z-stream (EUS).
I tried -128.1.6.el5 on my VAIO which was exhibiting the problem and things are fixed with the updated kernel. Just as a data-point.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.