Avast and Kerio Personal Firewall Issue

[joive]

I have Avast 4.6 home edition instaled. I also installed Kerio Personal Firewall 4.2.3. When I tried to use Firefox or Internet Explorer, after a few minutes comes a small window saying that there was an error and the browser needs to close. I checked and unchecked the settings in my main suspect first (firewall) but the problem continued. The only way to solve the problem is stopping the Network Shield on Avast from running. The window never come back. My questions are:

What protection do I lose when turning off the Network Shield? 

Does the Firewall compensates for that?

Common Problem?

ps. English is not my primary language, sorry if I mispelled something. I do know that the most important word in english is "Thanks".

[timcan]

Welcome joive to the forum. I see nothing wrong with your english
  The network shield analyses the network connection (intrusion  detection),which is what kerio does.I'm not sure if this is a commom issue between the 2 products or not but kerio should protect you well with shield off.There are many members here that use kerio that may be better able to tell you for sure.

[GrahamE]

Hi joive.

I've got Kerio 4.2.3 and Avast Home 4.6 installed. All of the Avast shields are running - I'm not certain what they all do, so I don't dare turn any off! I've never had a problem (well, not with THIS particular issue, anyway  )