Consistent HTTP status code 400 on AJAX

[rhkittredge]

I'm currently evaluating AbleCommerce using the demo site. For some reason I get consistent status code 400 errors when using the admin control panel.

Here is the exact error:

Sys.WebForms.PageRequestManagerServerErrorException: An unknown error occurred while processing the request on the server. The status code returned from the server was: 400

The only way I've found to solve this problem (albeit only for a short time) is to delete all the cookies attached to the site. I'm using Firefox 3.0.10 if that makes any difference. I did load it up under IE7 and the same problem happens eventually. I have been unable to determine what circumstances cause the error to start appearing.

Any help greatly appreciated!