Urgh, no it has nothing to do with that, do you want me to go google hunting until I find another review that spells it out more clearly? It takes the non-anamorphic source and converts it to Anamorphic - it has nothing to do with being able to play progressive while in 4:3 mode. HERE YOU ARE, END OF DISCUSSION:

The RP91 is a solidly built player that produces a very nice progressive image. I really like its autoscale feature. It automatically scales 4:3, letterbox, anamorphic, and non-anamorphic movies to their correct aspect ratio. This feature really shines in effortlessly scaling and playing non-anamorphic movies as anamorphic! The RP91 is the only unit in this price range that is capable of doing this. (A fellow enthusiast however submits that his JVC XV-D723GD also has that capability.) This feature is especially critical to owners of sets that have no image size control or lock to "Full" mode when sent a 480p signal. This player also has a littany of menu options for video and audio which adds to its flexibility to meet user preferences. I may actually get one not only for its autoscale feature but also for its audio (DVD-A) capability.

http://www.keohi.com/keohihdtv/videodevices/skyworth1050p/skyworth_minishootout.html

Go on tell me I still don't know what I'm talking about.