2.3.2 Image Browser works in FF but not IE

Hi,

I need help, i´ve got a strange Issue:

I ´ve installed FCKEditor on our local Server, worked directly via Remote on this Server and tested it in IE 6.0. Everything runs perfect.

Now i´ve loaded the Editor completely to our Webserver and run the Editor via URL in IE 6.0 everything runs except of the Image Browser (Click on Insert Image --> Search Server --> Bug). I get a "Internal Server Error 500".

When i try it with FF ist runs perfectly.
When i login on our Webserver via Remote and start a IE on this Server with the testurl, it runs perfectly, too.

Please help me the Editor has to run tomorow.

Greets Mario