I upgraded an ubuntu server from 10.04 to 12.04 more or less smoothly. However, I now can't contact it from my primary windows 7 laptop. I can contact other machines on the network from the laptop, and other machines on the network can talk to the server, so I am somewhat stumped. I haven't changed anything on the laptop, so can only guess it's a server issue. I've tried disabling the firewalls on both, without any effect. Any suggestions what to try or what logs to look at/enable?