Firewall dropping connections

[sieb@]

For some reason, for a while now, our server will start prematurely closing connections while serving web pages, especially if there is alot of content to download. Say I went to a website, half the pictures would not be loaded, or the whole page would not load. Hitting refresh helps sometimes. Restarting IPTables seems to do the trick, but I have to do it once every couple days. Anyone else notice this?

 

[sieb@]

If it was an Apache config problem, wouldn't it do it all the time? It appears to only do this once in a while and restarting the firewall clears it up, making me think its a firewall issue.