[old_tv_nut]

The data analyzer will not be much help, as the video signal consists of at least three levels: white, black, and sync. You need a scope to display it.

The monitor is a typical simple analog circuit in which the horizontal and vertical are independent and will sync whether the incoming signal is interlaced or progressive or even free-running ("random interlace," as it would be with an industrial video camera). Your video capture device is likely trying to lock the vertical and horizontal to each other at exactly the PAL standard, whereas the sync signal from the video generator board is likely progressive (meaning the horizontal frequency and/or the vertical is off from the PAL standard and their ratio is also different from PAL). My bet is that there is nothing wrong with the generator card, and it's just that your capture device doesn't like it.