VS 2010 Update Datagrid on form1 from form2

I have a datagrid(bound to a datasource) on form1, and when i click my add button i open form2 (bound to the same datasource) my details form. All is good, on form 2 I am trying to use:
My.Forms.tenantdetails.Paymentdetailsbindingsoure.Datasource = Me.PaymentsTableAdapter.GetData

It throws an error:
TenantDetails is not a member of TenantTracker2013.My.MyProject.MyForms

When I drop down the error combobox and pick any item it also throws an error:
Could not find the file c:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\big long number.vb

Any Ideas?

Thanks
LB