Can't connect using Windows 7

[raygr]

VNC Server PC has XP Pro and v1.0.8.2 using the SecureVNCPluginARC4.dsm plugin and has been running happily for some time. It sits on the internet and is accessed directly through an ADSL router.

Client 1 has XP Pro and v1.0.9.5 and connects without issues.

Client 2 is a Windows 7 32 bit laptop with v1.0.9.5 and can't connect at all. It uses the same SecureVNCPluginARC4.dsm and rc4.key as Client 1. I've opened the firewall for the VNC viewer, and I tried disabling the firewall altogether, but it didn't help. When it tries to connect it just sits at "Negotiate Protocol Version" and both "bytes sent" and "bytes received" stay at 0.

I suspect this is more of a Windows issue than VNC, but I'm not sure what to try next. Any suggestions anyone?

[B]

Not sure, but I was under the impression that the older encryption schemes were either broken or at least deprecated in 1.0.9.x. Why not try the 1.0.8.x viewer on the Windows 7 machine?

[raygr]

I don't think that's the problem, the existing client uses 1.0.9.5 and it works fine, and if there's an encryption problem then there's usually an error.

I'm suspicious about the lack of network traffic when it's trying to connect, it leads me to think that Windows is blocking the connection somehow.

[B]

Well you can certainly use a combination of netstat and telnetting to the listening ports to see what's going and to determine whether Windows is letting traffic pass. Of course you could also turn off the Windows Firewall and any other firewalling apps.