"Type not defined" message in VWD Express - but still works (sometimes)!

Hi

I am passing the parameter AimId to a UserControl called ucNodeGrid which I add adding to a placeholder called ListPatternPlaceholder with code like this...

                    'Add NodeGrid User Control
                    Dim ucNodeGrid As Control
                    ucNodeGrid = Page.LoadControl("~/DesktopModules/Pattern/ListPatternNodeGrid.ascx")

                    ' pass AimId to ListPatternNodeGrid.ascx

                    CType(ucNodeGrid, ListPatternNodeGrid).AimId = AimId

                    Me.ListPatternPlaceholder.Controls.Add(ucNodeGrid)

This works but VWD Express underlines ListPatternNodeGrid in the CType in a blue wavy line and says "Type defined not" ... however this compiles and runs OK

Except that I now want to pass two more parameters forward to ucNodeGrid, and this time all three give me ListPatternNodeGrid "Type not defined" and this time it certainly does not compile.

So my question is how do I pass several parameters to a User control in a way that VWD will like?

Many thanks

Geoffrey