Hi David,
Please have a look at the following forum where Grid with ObjectDataSource is discussed.
Forum discussion on GridGroupingWithObjectDataSource
You can download the sample from this forum and can change the version number in the register tag prefix for the sample to work on your system.
Also I have modified the sample from the above mentioned forum to much simpler form and attached the sample illutrates binding the gridgrouping control to objectDataSource.
GridGroupingWithObjectDataSource Sample
Please let us know if you need any furthur assistance
ThankYou for your interest in syncfusion products.
Regards,
A.Sivakumar