I have a laptop that is running Vista Ultimate SP1 and connected to a Windows SBS 2003 Server R2. Offline files have been working fine for the past 18 months but recently it would not sync correctly and showed up errors which I couldn't resolve. An assertion failure occurred for some old files, so I moved them out of the My Documents and into a folder which isn't available offline and the error still showed even though the files no longer existed!
I therefore decided to reset the sync database as detailed in Microsoft KB230738. Having left the laptop to resync the offline files (a few hours as there is about 30GB of data in My Documents) everything was available again and no errors were reported. I was working away from the office for the next few days so had created a new folder and created some documents inside it. Everything seemed to work OK for a few days but I then found that virtually all the offline folders were light in colour and most of them didn't have any files in them anymore or I got a file not found error if I tried to open any of the recent documents in Word / Powerpoint. The folder which I had created offline had also disappeared.
I had connected to the office network via a VPN a couple of times and also used VPN to connect to other networks which I support remotely. I also noticed that if I looked at the hard drive space I had 30GB more than after my initial succesful sync which probably indicates that Vista had deleted all the offline files.
I got back to the office and synched - which seemed to be fine but the work I had done whilst offline didn't reappear. I assumed that everything would be OK now as a successful synch had occured. However, I've been out of the office today and again, the same thing has happened. Offline files are available initially and working fine. I then connected to 2 other networks remotely using VPN, one after another, and after disconnecting all my offline files had disappeared and an extra 30GB of hard drive space is available again. When I get back to the office a full sync then began again.
Has anyone got any suggestions as to why the offline files disappear seemingly after I've used a VPN connection to connect to a different network? It's worked fine for the last 18 months!