We're running both VNC and PC Anywhere as a remote access utilities on quite a few machines. We have the routers across the board with the same firewall access rules. All routers also connect to a VPN server via IPSec.
We have one remote unit that works fine for web, vpn, etc. However, when we conntect via VNC or PC Anywhere, we simply get a black screen after authenticating. Oddly, if we plug in locally or tunnel in via VPN to connect w/ VNC or Pc Anywhere it works fine.
So... we're thinking it's the efficient 4100 DSL Modem? Maybe, we're not sure. We don't think it's our router, as we have the same settings everywhere and we've already played with settings, including MTU and fragmented packet handling.
It just doesn't make sense that it works locally and through the VPN. Our ISP of course refuses to take any heat and claims the FIREWALL is off on their router (the Efficient).
And yes, we even replaced the PC.