Error Could not load type ‘System.Data.Services

Hello Again,
This time I have an issue with my Microsoft Groove software. I keep getting error messages that it could not load the file type.
This is what I am trying to do; I am trying to access the REST web services, through SharePoint and am receiving the following error message.
I hope someone would have come across this error message. Please help.
Error
Could not load
type ‘System.Data.Services.Providers.IDataServiceUpdateProvider’ from
assembly ‘System.Data.Services, Version= 3.5.0.0, Culture=neutral,
PublicKeyToken=b77a5c561934089’.
Troubleshoot issues with Microsoft SharePoint Foundation.
