CentOS 5.5 in Hyper-V LIS install problem

Hey guys,

Hoping for some help with this issue I'm stuck on. Sorry about bring a little MS over to the sub! Trying to get a specific server to run in Hyper-V and I want to install the integration services so I can use the synthetic NIC. Kernel is 2.6.18-274.18.1.el5PAE (the only one installed). I installed version 3.5 of the Linux Integration Services and the install went fine, but the modules are not loading after a reboot. If I try to use modprobe for hv_vmbus it gives the error Invalid module format. Modinfo vermagic shows 2.6.18-194.el5PAE, could that be the issue? LIS 3.5 says it supports CentOS 5.5, but maybe I need to just use an older version like 2.1 that can be compiled?

I need to get this done without upgrading the kernel if possible. Any ideas on where to go from here? I'd appreciate any ideas.

Thanks!