Classifieds Plugin Will Not Crop a Picture

When I am placing an Ad, and I get to the part where it allows me to upload a picture, Once i try to upload it gives me the following error:
Warning: getimagesize( [function.getimagesize]: failed to open stream: HTTP request failed! HTTP/1.1 401 Authorization Required in ~/c4ff/wp-content/mu-plugins/classifieds/classifieds-core.php on line 1470

In Internet Explorer The error occurs and my image is never uploaded.
In Firefox, the error occurs but my image is uploaded. odd.