Offline Folders, VPNs, & WiFi

I have a WinXP Pro SP2 laptop that connects to a Windows 2000 Server SP4
domain network at home and on the road. At home, it connects through a
regular Ethernet wired connection, and has reliable connectivity with the
domain controller. On the road, I connect through Wi-Fi and VPN mostly.

I used offline folders extensively between my laptop and my home Win2K
server. Anytime I connect with Wi-Fi and VPN, I always seem to end up with
problems if the VPN drops or I want to simply use the internet after
disconnecting from the VPN. The offline folders go offline, but when I try
to access the offline version of the folders, I get an error message that the
computer cannot contact the domain controller, and explorer will often not
respond.

Is there a way to tell XP that when the VPN is not connected but the WiFi
still is, for it not to try to communicate with the online version of offline
folders or domain controller.

I've tried using csccmd.exe /disconnect:\\SERVER\offline_share to force it,
but that doesn't avoid the domain controller error and non-responsive
explorer.

Is there a way for the cache and domain controller connection to go
immediately offline when the VPN disconnects but WiFi remains connected?