GetMap request does not allow for null STYLES parameter.

Issued following request:
http://beta.openplans.org/geoserver/wms?LAYERS=cblf:Ponds,cgf:Lines,cblf:BuildingCenters&FORMAT=image/jpeg&HEIGHT=400&REQUEST=GetMap&BBOX=-74.27,40.5,-73.8,40.94&WIDTH=400&STYLES=&SRS=EPSG:32615&VERSION=1.1.1

Response:
org.vfny.geoserver.WmsException: 3 layers requested, but found 1 styles specified. Since SLD parameter is not yet implemented, the STYLES parameter is mandatory and MUST have exactly one value per requested layer

From the WMS Spec:
A client may request teh default Style using a null value (as in "STYLES="). If several layers are requested with a mixture of named and default styles, the STYLES parameter includes null values between commas (as in "STYLES=style1,,style2,,"). If all layers are to be shown using the default style, either the form "STYLES=" or "STYLES=,,," is valid.