Consuming WMS layers in ArcGIS Desktop from Mapguide

I'm having an issue consuming WMS layers exposed via Autodesk Mapguide Infrastructure Server within ArcGIS Desktop 10.

ArcGIS Desktop 10 is submitting the request as follows:

http://www2.wtgroupllc.com:14088/map...ANSPARENT=TRUE

My Mapguide server throws an error that the request is not valid. (Can be confirmed by attempting the request via a web browser)

Editing the request to:

http://www2.wtgroupllc.com:14088/map...ANSPARENT=TRUE

Will successfully retrieve the layer.

Is it possible to edit the parameters of a WMS request within ArcGIS desktop?