Hyper-V + Opteron 6100 + RHEL5 = Kernel panic - not syncing: Fatal exception

I'm trying out Hyper-V on Windows Server 2008 R2. My first attempt is to create a VM running Red Hat 5.5. This is what I get after the initial screen:

The VM has 2GB of memory which should be plenty (I upped it to 4GB and got the same result). I get a slightly different message when using 32-bit instead of 64-bit:

I'm using a legacy virtual network adapter as the documentation suggests. Hints are welcome. This is on a Dell PowerEdge R815 with two AMD Opteron 6100's and 40GB of RAM.

Update: Thanks to Heine for pointing me to this bug.