Since we have moved to 6.3R4, our Network Connect users have had problems connecting to the SSL VPN Gateways. They have been receiving the 23790 error when trying to connect. We found that the expections in the web browser were causing this issue. If you have an exception with *juniper.net, the Network Connect client will not allow the user to connect at all; however, if you change the exception to *.juniper.net, then the client works fine. This problem did not happen in 6.3R3. Hope this helps anyone who is having the same problem.