OK I solved this one. When I had those socket errors I was indeed updating tv-server quite often. Now I hadn't updated it for a while and Web Interface also kept working well. Then I updated it yesterday again and Web Interface kept working after tv-service update BUT after reboot web interface was again giving socket errors when trying to open manager. Pressing Save to reboot interface (from manager) did report web interface was rebooting but it didn't help. What helped was manually terminating webint.exe process and manager and then starting service again from webint manager. It's weird that it works well after update but not after reboot..I think version 0.1.2.9 is last one which is worked somehow well on my system. After that I can't connect to web int after about 24 hours of installation. When I open manager on 2.0.0.06 I get Socket Error #10061 Connection refused so it could be a firewall issue also, but previous versions (pre 2.0.0.00) worked..
EDIT
If I manually kill the process MPWebInt.exe and start it again, it works! It just doesn't seem to work automatically on computer restart.
Hmmm. now it works again flawlessy. I've been updating Tv-server quite often lately. It could also be a situtation where tv-server has been uninstalled and installed but web int hasn't been shutdown on the process. Even then after reboot web int doesn't wake up if it isn't shutted down and restarted. I'll test this next time I update tv-server.