It seems to me your Comodo firewall is causing more conflict problems than it's worth and you would probably do better to dump it (and Avira) and keep Avast.
In any case, the Windows 7 firewall is a good one, and if you are using a modern router, it probably has a firewall as well, so there is no real need to use Comodo at all, especially if it's the major cause of your conflict problems.