Dead connection after some time

Dear Helpers:

When I use Comodo for some time, for example, 1 hours, the network connection will be dead( both wired and wireless). Even I use allow all or exit Comodo, it doesnot work. I have to reboot my pc to make a new connection.

Also, another question, when I restart my pc and if there is no network connection, I cannot connet network any more until I quit Comodo, why?

Thanks.

Steven.