Problem with browsing for images / files when trying to access images / files

[scotch33]

Hi there,
when clicking the 'browse' icon from within images or withing 'add link' I am getting the following error instead of the list of available files.  i need to tell the client's hosts to see what can be done.  has anyone seen this / solved this before.  When the same site is running on my server there is no problem so it must be something on their hosts...

Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@driverdefenceservice.co.uk and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Apache/1.3.41 Server at www.driverdefenceservice.co.uk Port 80

Thanks!

john