i have several dell poweredge 2650s with 4gb ram (these are 32 bit xeon cpus) running fc5 w/ the 2.6.17-1.2174_FC5xen0 kernel, the domUs are ubuntu dapper images booting the 2.6.17-1.2174_FC5xenU kernel. everything works beautifully, very stable. i was hoping to squeeze some more domUs on these systems by adding additonal ram and using the PAE kernels. unfortunately booting 2.6.17-1.2174_FC5xen in the dom0 breaks networking (the bridges are no longer created) and the domU won''t boot at all (kernel panic, can''t find /dev/sda). i''ve also tried the latest fc5 kernel and the stock fc6 kernel and get the same result. i''ve copied lib/modules/2.6.17-1.2174_FC5xen to the domU''s root filesystem and am using the matching initrd but no joy. is it possible to make this arrangement work?