I have a WSS 3.0 server running on Windows 2003 HyperV vm. My network is on a 192.168.1.x and I have a 2nd network on 192.168.10.x. Occasionally I have users on both networks experience connections issues to the WSS server, They all use IE8. They will get a 'OOPS! Internet Explorer cannot connect to Sharepoint' They can reboot their computer and it seems to fix itself for awhile. I have a wireshark capture from one machine and see the connection being made but on the last packet coming from the WSS server it shows red. Not sure if the color code means anything.
I am not sure how to post a wireshark capture since it is 16MB.
My WSS server as well as all my other servers has a persistent route added to point to the 192.168.10.0 network. I can ping the WSS server from a client that is having the issue and it resolves the server name and IP. Trace route seems fine.