[CentOS] "BUG: soft lockup - CPU#n stuck for X s! [swapper:0]"

I just updated my quad-processor X64 machine (AMD Phenom(tm) II X4 945 Processor) to the latest CentOS 5 xen kernel (2.6.18-371.4.1.el5xen) and I am getting occasional "BUG: soft lockup - CPU#n stuck for X s! [swapper:0]" messages. I did some net searching, and found some bugzilla reports (https://bugzilla.redhat.com/show_bug.cgi?id=649519 and http://bugs.centos.org/view.php?id=4488), but neither are shown as resolved. The machine *seems* to be running alright (it is not hanging or anything). Is this something I need to worry about? Should I revert to the older kernel (2.6.18-371.3.1.el5xen)? This is NOT happening on my single-processor 32-bit laptop (running 2.6.18-371.4.1.el5).