Cant upload Joomla Templates. Can upload files and pictures

[morten44]

Hi again
Stuck with another problem regarding Joomla
I have used this manual to install ISPConfig
http://www.howtoforge.com/perfect-se...10-ispconfig-3

I can upload my Joomla files using FTP and Install it
I uploaded it as a zip file and used aceba backup file "kickstart.php" to unzip remove and install via web.

I can upload pictures to media manager
All ok

What I can not do is to upload templates and modules.
I did however manage to install a small plugin,not sure why.
I am sure the modules and templates I install are not more than 1MB and the error comes with 10sec

I says
ERROR 500 - Internal Server Error
The Following error occured
The requested URL caused an internal server error.

I read some other articles about this like thins one:
http://www.howtoforge.com/forums/arc...p/t-20062.html

but I am using FAST-Cgi

When creating the website i tick off:
SuEXEC
Own Error-Documents
PHP -> FAST-CGI

I have problems understanding the whole permission thing depending on what "owns" the files but i through I had understood that if I uploaded the files with FTP and used FAST-CGI i should be able to use all Joomla functionallities like upload and install templates

Any idea where I have to look for the problem?

Thanks gain

Regards
Morten