Hi Rick,
I would broaden my advice to don't use any UserControl in a grid if that UserControl makes any database hits. It basically an architectural and performance anti pattern. I mean it can be ok like inside an EditItemTemplate of an editable grid but not an ItemTemplate, because when editing its just the active row where the extra db access will occur. Its particularly bad if the grid is binding to an IDataReader because it has an open connection with the db while it databinds and if more things are making data requests you are using multiple connections at once.
You should generally design it so that all the data needed by the grid is in the result set. If its a situation where you need a master/detail kind of grid you can create a DataSet with multiple data tables in it connected by datarelations. One place in mojoportal code where you can see an example of constructing such a DataSet is in the WebStore.Business project in the Store.cs line 565 GetProductPageWithOffers.
I would not use a Grid to layout feature rich controls that do internal data access.
Hope it helps,
Joe