Images and Video same playlist

Hello,
I have 4 HD210's with firmware 3.1.73 installed. We use BrightAuthor over the network to publish to an internal IIS http site (the post I found in this forum to open up the file extensions used by Roku in IIS were used and after that IIS worked) The units are working great playing back 720P (1280X720) MPEG2 in a full size frame of the same resolution to hdtv's connected via HDMI and with HD210 sign properties set at the same resolution. Changes made, saved and published to the IIS server are updated on the units properly after about 10 minutes (they check for updates every minute).

Up until this point I have just used MPEG2 video content in my playlist. I have tried several times to put images in the playlist as well (in .jpg format; most are 1024X768 Resolution), placing them between each video in the playlist using BrightAuthor. I save and publish this new content and the HD210's seem to reload the content (they go blank for a while) but only play the videos, not the images. Does anyone here have any suggestions that I could try to fix this issue I am having? I would really like to have a playlist that includes both Video and Images intermixed.
Thanks,
Mark