I have a virtual machine on ESXi 4.1 U1 running Windows Server 2003 x32. The machine cycles through 7F stop errors on restart, but if you power off the machine and power back on, it boots and runs fine.
The machine was moved from a different ESXi 4.0 server and VMware Tools upgraded. Attempted an uninstall/reinstall with same results.
I'm assuming you have other VM's with the same OS on this 4.1 host that aren't exhibiting the same problems???