Slow Link Detection Nadgering Offline Files!?

Hi,

We have our users 'My Documents' folder redirected to a mapped drive on the
server, it is then setup as an offline folder. This worked fine for mobile
users who would come in and out of the office to sync. However, since we put
in our VPN, users have been complaining that offline files tries to sync
over the VPN, which can cause it to be very slow. This even happens if
someone is in word, and tries to open a file from their My Documents folder,
as it seems to try and pull a directory listing down across VPN, rather than
locally.
I have a group policy setup with 'Configure Slow Link Speed' set to 5000
(bps /100) which should cover everyone's ADSL connections. However, even
with this set, it didn't seem to be taking any notice of the speed set, and
just kept trying to sync. So having looked into this problem, I found that
MS said it was a known problem (which should have been fixed in XP SP2) that
it could possibly be fixed by adding the following reg key.
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Net Cache]
"GoOfflineOnSlowLink"=dword:00000001

However after adding this key to everyone, I found that it seemed to fix the
VPN users issue, but then when they came in to the office, it kept setting
them to offline mode, even though we are on a 100mbs network. It seems to
happen every 5 minutes, or when the users are accessing their 'My Documents'
folder, it just sends them straight into offline mode, and they have to
click on the little offline computer in the taskbar to re-connect and sync.
As you can imagine, it's becoming very irritating for users who access their
'My Documents' folder regularly. I have tried changing the slow link speed,
setting it to 2560, 5000, 7500, and 10240 bps /100, to see if that made any
difference, however it doesn't seem to have any effect.

How can I configure this, so that VPN users can work offline, but office
users stay online? We're using Win 2003 server SP1, and WinXp SP2.

Any help very greatly appreciated!

Ben




Ben