I have the same problem with my Daughters TV Wonder Pro. I found that closing and re-opening the program would correct the problem. After some toying around I found that it seems to happen when I would re-size the Window that the TV was playing in. I honestly can't remember if it happens more in small Windows or large. I never told my Daughter how to fix it because it was so slight, she has never complained about it. Try re-sizing the Window, I think it will go away.
The more I think about it, I think that I set it to open up in a 'Full Screen' and that ended the problem. I think that starting in a small Window and then re-sizing to a full Window would cause the speech delay. Setting the program to open in a Full Window eliminated the problem (that is the way I am remembering it, I'd have to sit down and mess with it for a while to actually see what I did). Besides, that is the way she uses the TV Tuner, Full screen, how many people watch in tiny Windows?
The problem is so slight on my Daughters rig that I am keeping my eye out for another ATI TV Tuner for my rig (I already have an extra Remote Wonder).
BTW: HDTVMan, I got the TV Tuner card because my Wife wanted me to install a TV in my Daughters room. I didn't want to have to mount the bracket on the wall and have to worry about glare (there are windows on 2 walls in her room). Also, since she is a 12yr old girl, I figure that in a few years she will want to be re-arranging her room every week or so and I certainly wasn't going to re-mount a TV all over the place! Besides, with a 17' LCD and a set of 5.1 speakers in her room already, the TV Tuner card is a perfect match.