This is a known libc configuration mismatch between stock Fedora Core 6 and Xen/Fedora. See: http://lists.xensource.com/archives/html/xen-users/2006-11/msg00034.html [1]
To fix (quoting from the link above): echo 'hwcap 0 nosegneg' > /etc/ld.so.conf.d/libc6-xen.conf in your Xen domU
Links: ------ [1] http://lists.xensource.com/archives/html/xen-users/2006-11/msg00034.html