Try reinstalling Comodo. Reboot and delete all folders related to Comodo Internet Security. Then let a thorough registry cleaner clean the registry. You can try Comodo System Cleaner: http://system-cleaner.comodo.com/index.html .
I am having the same problem plus CPU usage seems to be higher (it is really higher w/ Firefox - something else I need to look at). The Application Agent not running just started in the past week or so. I am at .439 which I think is the latest, I am concerned not having firewall. What is the solution and what introduced this problem of the firewall not starting.
Also tells me to run Diagnostics which I do but tells me there are no issues.