OK. The slider does not change the video screen frame displayed. After I move the slider to another position, then hit play, it starts playing from the new position of the slider. Frame advence, forward and back, does not change the screen frame displayed. I don't get a black screen. I did not edit any video...so it happens with an unedited file. The video I am using works fine with my V.2.0.1104.27 of WMP Trimmer on my old computer with Windows XP.
Do I need to try and edit the video and send it to you, or is there something I can try first?