adding images with fck editor

When I open an information page and edit with the fck editor, I cannot add any images to the page with the image button on the tool bar.  When you try to browse the server or upload images a big grey box opens and at the top is says:
The server didn't send back a proper xml response.

There is some other text I don't understand but looks like it is referencing a connector.asp file?

Uploading other pictures for products via the image page all work fine. I have 0.7.7

Any ideas on how to correct this?

thanks!