Whenever I activate (my only defined) VPN connection, my FTP client can't
upload files. I assume this is because all Internet traffic goes through the
network on the other side of the VPN, and this causes some problem with FTP
authentication.

Is there a way for me to force a program (e.g. my FTP client) to use my
normal Internet connection, even when the VPN is connected?

Yes, it sounds like routing issue. This search result may help,

routing issues on vpnCase Study – peer to peer route via VPN connection ... Resolution: When establishing VPN to the office A, the routing table changes. To fix this issue, ...
      http://www.chicagotech.net/routingissuesonvpn.htm


Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com
  Whenever I activate (my only defined) VPN connection, my FTP client can't
  upload files. I assume this is because all Internet traffic goes through the
  network on the other side of the VPN, and this causes some problem with FTP
  authentication.

  Is there a way for me to force a program (e.g. my FTP client) to use my
  normal Internet connection, even when the VPN is connected?

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