Subclassing DataGrid

[Dan]

Hi,

I am working from some examples in the MSPRess book: Building web solutions with ASP.NET and ADO.NET by Dino Esposito. I have subclassed DataGrid, and created a MyGrid class, that encapsulates some common behaviour I want. Now before I would have

<aspataGrid...><Columns....></Columns></aspataGrid

Now I hav

<mine:MyGrid...><Columns....></Columns></mine:MyGrid

but in design mode I get red lines (indicating an error) under the <Columns> tags, saying the active schema does not support this. This means the intellisense doesn't work etc, which is a pain. However, it does all compile and work OK, but it's a pain to edit, because it's hard to pick up mistakes. Is there a way to solve this?

Thank

Dan