Firewall Problems?

[Ajazza]

Hi,
I am not sure what is happening... but my site www.musicbroker.com.au is sometimes working and sometimes not.
Whenever it stops working... I have to put the firewall in to opposite state... if it is on I have to set it to off and then my site works for awhile until I have to change it back again..
What can cause this... also I can only ftp using SFTP using SSH - how can I change this?

Thankyou for a great product and help
Adam

[falko]

Is your server in a local network, behind a router, or is it connected directly to the internet?
Which firewall do you use? The ISPConfig firewall, or another one? What's the output of

iptables -L

?