I'm probably not reporting anything new to anyone who has spent more than a few minutes playing around with the .NET tab control but is really does suck :( It lacks so many features I'm not even going to bother listing them all now. However, it has given me an excuse to develop an extension library (that hopefully one day will make it into a full blown control) for the tab control.
The first issue I sorted out was enabling a tab to be made invisible. I have a fix but it needs some work doing to it before I'll post it. Hopefully I'll get this sorted within the next few days. Next on my list of features to sort out is providing a feature to grey out the tab text for disabled tabs. Currently if you disable a tab it just disables all the controls on the tab but not the tab itself.
I will try and come up with a list of features the tab control is missing and try and resolve them one by one in the extension component. Should be an interesting little project to get myself familiar with controls in VB.NET.