virtualbox.org

Installed VBox 4.1.6 , with Windows 7 guest on a Macbook 13" (OSX 10.6. and the screen does not resize; I've installed the guest additions twice, and each time it indicated that the install succeeded and I had to reboot the guest.

Mouse capture works, but automatic resizing does not...the Windows screen is 'stuck' at 1024 x 768 and resizing the VBox window on the mac just reveals scroll bars to move around the Windows screen.

Try the host+G toggle to make sure that auto-resize is enabled.

Tried that, and it is selected in the menu, but still not working. Unfortunately it's a staff members system and I don't have hands in it right now...

Try doing host+A

Or View > Adjust Window Size

I had a similar problem until I did that. Don't recall having to do that before but it worked for me. See if it works for you.