TV Wonder PCI Tuning issue under 2k or XP

[flashbak]

I've noticed that certain channels that are stereo sometimes come in mono in one direction of tuning them in and stereo in another. For example, if I use the channel up button from channel 18 to channel 19 that signal is stereo, however, if I'm at channel 20 and use the down channel button to go to 19 it becomes mono. If I instead use the keyboard numbers for direct channel switching (down direction) I have to key in channel 19 twice since the first time it will be mono and the second keying turns it to stereo. I've also noticed that occasionally it works fine but most times it doesn't. This problem exists under both Windows 2000 and Windows XP. Has anyone else noticed this anomaly with the WDM/MMC 7.1 software? Please note that this problem isn't experienced at all with PowerDVD II 3.0 which leads me to believe it is in the software.