Hi
I have just tried this procedure out with my A/D "One Touch Grabber" card and Yes, VP loads both video and sound direct via the Record button.
It wouldn't be necessary in fact to use the "Grabber" software that came with this little device although the interface for this allows you watch the tape and to check the contrast and colours etc. before you set it off recording. So I create an avi file first and then subsequently load this into VP.
However, although not the same as the Vidbox with regards the leads, my variant of the "Grabber" has the 3 composite connectors plus the svideo plug that connect to the tape player and at the other end the USB input cable to the computer plus a separate audio 3.5 mm colour coded jack plug. This jack plug is Pale Green. (Note: most of the "Grabbers" don't seem to have this particular cable but it may be relevant)
When I first used this device it failed to record the tape audio in the output video but as it was colour coded I had logically plugged it into the green audio socket on my PC. However that was the earphone socket. I needed to plug it into the Pink microphone socket! if your leads are similar it might be worth checking out. Audio Out should go into the microphone input.
Also check the VP mike input recording setup. Click the Red Record button on the toolbar and then select Record Audio. Here you can check the Windows record mixer as well as make a VP test audio input.
Nat