I got this error when migrate form esx2 server to another esx3 server and choosing a different datastore location vmfs3
"General fault caused by file.
Thanks for your assistance.
are you sure that you use already the .vmdk extension for your machines, or maybe the older dsk ? If yes, open the MUI on the old server, remove the given diskfile, and rename this disk 1st with the vmdk extention, after that give the renamed disk back to the machine and try again.
If you use a ESX server version below 2.5.3 you cant migrate the machines, you have to clone them - thats at least that what I figured out while migrating our machines.