Forum rules
When you use a 3rd party SEF extension, you need to turn off JFrouter. The SEF extension should take care of the routing of your URL's

First check if you are running the latest available versions of Joomla! (1.5.18), Joom!Fish (2.0.4) and the SEF extension you're having problems with.

We need the following at least (you can find this in your Joomla! backend under help > system info):

* Joomla! version
* Joom!Fish version
* SEF-Extension version
* PHP version (e.g. 5.2.5). Note: The support for PHP4 is discontinued.
* Web Server software (Apache or IIS with version number if possible)
* Server Operating system (e.g. Linux, Windows, Solaris, Darwin ...)
* Webserver to PHP interface
* Database version
* memory_limit from your phpinfo

Please enable error reporting and include any error messages in your posting.

Finally, please describe the steps required to recreate the problem and also please enable error reporting and give us any error messages generated.