No. You are not wrong. Dscaler doesn't care what drivers you have installed for other applications.
I have a Pinnacle card. In preparation for upgrading to WinXP, I uninstalled all of the Pinnacle apps, including the drivers. After my upgrade, when I checked the device manager, sure enough - I had question marks in the "Sound & Video devices" category for the Pinnacle card - no drivers. But Dscaler still worked like a champ.