I've removed the Winforms.UI reference as it didn't need be there.
The problem isn't during runtime, it behaves properly when you execute. The issue is if you open Form1 as it is then you will be presented with a form, my custom tab control and a few tab pages already added .... Because these pages are 'already added' then I am unable to select a tab page or click a close button .... however if I then select the tab control and click the smart tag and click 'Add View Page' then another tab will be added and this tab page and any further ones added will then work correctly (however the other 'already added' tabs still do not).
So essentially what is happening is you add a tab page to the tab control, that then gets serialized in the designer.vb file so next time you open the form or it rebuilds then everything will get constructed again on screen, but it seems that this causes it loose the ability to work in design time.
that make sense? I've tried so many different ways to resolve this with no effect, but it seems to me like it should work as it is :(
Jamie.