samba - Feb 2008 - Loading profile slow over a fast wan link

Logging on  with XP, with our desktop profile across a 10mbps wan,  
takes a LONG time to transfer even just 5mb of profile data.  Any 
suggestion on tweaks to speed this up would be greatly appreciated.  
Other protocols like ftp, rcp and scp are 10 to 20 times faster.

Regards

Douglas Phillipson