I will try and make this short (I said try)...I had a Nook HD+ 32GB and ended up installing Cyanogenmod on it and giving it over to my teenage daughter. I liked the device and you cannot beat the price so I went and purchased a new one for me and I was going to install Cyanogenmod on it as well but never did. The thing is bone stock. All I have been using it for are my books I have purchased through Barnes and Noble and movies that I have converted to the appropriate .mp4 format and copied over. I had a movie that I copied over last night that was already in the .avi format and I was going to watch it today at lunch. I had forgot that Nook does not support .avi......or does it? I selected the file from my library and it says that it was not a supported file so I started doing research. Sure enough, everything I read states the same thing, that the format is not supported. At this time I started trying to get the file to transfer over to an ipad that I have at work so I could watch the movie. I installed Fast File Transfer and File Manager HD (Tablet) from Rhythm Software. I opened up File Manager....located the .avi file and I noticed that the icon showed as a clip from the movie as if the device recognized the file. I selected it (drumroll for effect) and it started playing. I quickly shut it down and went back to the library on the device and selected it...says that the format is unsupported. Go back into File Manager and select the file...and it plays. This device is stock. I do not have any other video player installed and when it's playing the file it's clearly using the stock player that it uses when it plays the .mp4 files. Any insight on why they claim the device cannot play .avi files but it clearly does without issue?