This bug has been copied from bug #518104 and has been proposed to be backported to 5.4 z-stream (EUS).
Fix built into xen-3.0.3-94.el5_4.1
I verify this bug by the following steps: (1) Create a PV domain (2) Reboot it (3) Repeat 2. After I reboot the guest for 11 times, and find no more any crash. Seems the problem is not exist now. So this bug is verified with the xen-3.0.3-94.el5_4.1
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. http://rhn.redhat.com/errata/RHSA-2009-1472.html