I believe I have some issues with the tab control at design time:
Create a new project and add a tab control through the designer.
Click on the tab to select TabPage1
Add controls to tabPage1 – I’m not sure the tab has actually been selected and the controls all end up in the top left corner of the page at runtime. If I switch to tabpage2 and then back I cannot see what I have added.
Click on the tab to select TabPage2
Add controls to tabPage2 – you can see the page and the controls stay where you drop them , clicking on tab1 and then back and they are still there but close and reopen the project and clicking on either tab does not display the page.