OData for Calc. view - Parameter problems

Hi,

i need some help with the input parameters of an OData service. I'm trying to consume a calculation view via a OData service which has three parameters.

- P_DATEFROM (Date)

- P_DATETO   (Date)

- P_REGION (String)

I used a similiar definition like here: http://scn.sap.com/community/developer-center/hana/blog/2013/01/22/rest-your-models-on-sap-hana-xs

The definition of the service works fine, but if i try to open it with some parameters i receive an error:

http://server:port/path/service.xsodata/InputParams(P_DATEFROM='2012-01-11',P_DATETO='2012-01-15',P_REGION='BIN')/Results?$select=NAME,REGION

=> Illegal query syntax.

I'm not sure what is wrong, but i think the date format is not 100% right and i can't figure out what.

Thanks and best regards.

Manu