Wireless disconnects frequently when using VPN

I use Cisco VPN on a laptop (Dell Latitude D610) to connect to company network from home. Without connecting to VPN, the wireless (Intel 2200BG) connects fine. Whenever I connects to company network with VPN and start working (using web tools and FTP), it disconnects every couple of minutes. Then it would auto-connects but my VPN is disconnected. I would have to reconnect. If I don’t do anything relating to VPN, the connection stays on. If I connect the internet on cable, it’s fine. Unfortunately, my cable connection is in the basement which very cold in the winter.

Any solutions??

Thanks,