I''ve been attempting to use my machine with a Matrox Parhelia card with the Fedora Core 6 Xen kernel. The Matrox card requires a kernel module. The module builds without error, but fails to load due to an unknown symbol, "cpu_callout_map". I submitted this issue to the Unofficial Matrox Technical Support Forum, but haven''t been able to resolve anything yet: http://matrox.tuxx-home.at/viewtopic.php?t=185 I''ve also submitted this question to the xen-users mailing list who asked that I try here (the fedora-xen list) first. Any thoughts on how to resolve this problem? How would I find out what the function of cpu_callout_map is and why it is being compiled into the mtx module? Any idea if this is a general Xen issue or is it FC6 specific? Many thanks for your help, Vann