Vista - Slow VPC, CPU shows as mhz, NIC driver problems

I have a VM (Windows Vista Ultimate Edition) running in Virtual PC 2007
sitting on a Windows Server 2008 host. The guest OS system is painfully and
ridiculously slow.

My main concern is that when I boot up the guest OS it can't seem to find
the network drivers. Every now and again it will, they load up and
everything is fine, but then it just "forgets" about them again and I get the
(Code 10) error with no connectivity.

Also, my CPU shows as 2.88ghz but only seems to be operating at 20mhz
according to the guest Vista. The host system I have the VM running on is
3.0G Intel with 3gb of physical ram. I have allocated 1gb of ram to the
virtual machine which should be enough for a dumbed down vista to run. I'm
not looking for AERO or anything, but currently regardless if I'm running the
VM in VPC2007SP1 or VS2005SP1 it seems to eat up ALL of the resources of the
host and guest machine.

I have installed the most recent of the VMAdditions (appropriately depending
on if I'm running in VPC2007SP1 or VS2005SP1) and all KB's I could find on
the host and the guest to no avail. I have reinstalled the OS 3 times to
make sure it wasn't just something to do with the install and I still have
the same issues. I have some XP vm's that work fine on VPCSP1 and VSSP1 so I
don't think it's the install or the host computer exactly. Also, I have
uninstalled both VPC and VSSP1 a couple times to eliminate that possibility
as well.

Any suggestions are welcome.