Problem with URL after Response.Redirect

I just upgraded my asp.net site to asp.net 4.0. However, many of the links in my application have code like this:
Response.Redirect("ReportSubUpdate.aspx?rsID=" & GridView1.SelectedDataKey.Value)
The url should be:
https://www.etrailtoeagle.com/dtg/ReportSubUpdate?rsID=4235
Instead it is:
...