Access 2000 to Access 2007 bug

[John]

Hi

I have converted my Access 2000 app to 2007 by opening it in Access 2007 and
using Save As. The main form in the app has a tab control with a toggle
button set on first tab. The problem I am getting after conversion is that
when the main form loads, clicking on toggle buttons don't work ie the
buttons do not change state. However if I click on second tab and then back
on first tab then the toggle buttons work. What is the problem and how can I
fix it?

Thanks

Regards