Here it is finally... ( note , I did not write this )
Whitepaper Configuring and Troubleshooting Certificate Services Client–Credential Roaming...
Should answer a lot of the questions I got in response to my previous posts on DIMS ( Credential Roaming ) which is built into XP.
A few notes - it wont work with remote file encryption.
Too bad since remote file encryption's general response is " use roaming profiles" but with XP and a Vista roaming profile it wont work :(