problem with tosh picture frame 2

[shortround]

i have the 36zp38. i prefer to have it in progress mode when viewing interlaced material as i believe it drops down to 50hz and i don't like the motion blur that occurs in the 100hz modes.

it's fine when watching 50hz pictures (sky digibox, dvd etc) but when i view a 60hz ntsc dvd the bottom of the screen about an inch high gives a strange effect. it's as if the scan lines have been zoomed to twice as large as normal. it only occurs when there is motion in the shot so static images look normal.

this problem doesn't occur when the tv is in any of the 100hz modes. i've also checked it with 2 dvd players and various dvds so i know its not the player.

anyone else noticed this problem? could it be that when selecting progress mode the tv locks itself to a 50hz refresh rate and stays like this even though its being fed a 60hz signal?

thanks in advance for any help.