Portable Home Directories

Desperately in need of help here. We have recently migrated from an OD to AD, but are now running the golden triangle setup. Previously our countless number of MacBooks were set up with Portable Home Directories with all of the settings and rules managed from WGM. PHD worked very seamlessly and users were very happy. We are still managing the settings for Mobility from WGM, but all home directories now live on a Windows 2008 server and are shared via SMB. The problem now is that PHD have become a nightmare. Every time a user logs in, Mac OS X will run a check on all of their data (up to 15GB in some cases) before syncing, rather than only syncing the minor changes. Even during a background sync, it will run a check on every piece of data. What am I missing? Can someone share their experiences and possibly their WGM settings for Mobility? This is driving me insane. I am now also having problems with getting any sync action when initially creating a Mobile Home!