Frink, there is actually a Pro version of Vegas Studio. Sony's nomenclature can certainly be confusing at times! :)
Pagz, the procedure you followed, using Forced Film, might have left blended frames if the removal of the pulldown was not completely successful. You might try selecting "Honor Pulldown Flags" when you first make your lagarith AVI (prior to editing) and writing a script to inverse telecine if none of Adywan's information helps you.