Installed ispconfig3 on centos5.2, seems to work quite well! Was puzzling over the client templates however; when editing client limits, the tabs "Add additional template", and "delete additional template" do not seem to function. Also, I'm probably doing something wrong somewhere, but Addon templates seem to have no effect on the limits.
I'd guess in case of FF it's helpful to have a list of addons / plugins esp. such stuff like noscript etc. that might break any functionality.
No FF extensions are installed. Just gave it a try on Safari as well, same behaviour. So at least it's consistent I'm on the latest svn revision as well (867 I believe).
@ all there was a error in this function some times ago. First it works, then the error occours (arrrrrgh copy and paste). i fixed this error some times ago in the svn. maybe you have different versions. please get the newest version and try it again.