In Css and Custom Server Controls I talked briefly about a problem with the mark-up for my server controls being injected with   after toggling to Design View.  It was certainly something I could work around, but it was annoying nevertheless.  I just couldn't see anything in my designer code that could cause the issue.

Well, I recently reviewed the Visual Web Developer Team Blog about the multiple fixes included with VS 2008 SP1.  Under the WebForm /HTML Design View subheader, there is an item that looked familiar:

• Many NBSPs added and tag name corruption when editing a page that uses Telerik controls (popular custom controls)
  http://forums.asp.net/t/1185266.aspx

I wondered if this could possibly be the same issue I was experiencing.  I had already installed SP1, so I went to one of my "problem" pages and toggled to Design View (I have mine set to default to Source View).  I made a minor change while in Design View to trigger an update to the markup and switched back to Source View.  No NBSPs!  Now I can share my controls with the rest of the team without attaching a disclaimer.  Woo-hoo!