I just flashed one of my N900s with the image for PR1.3.1 here:

http://nds2.fds-fire.nokia.com/fdp/i...ED_MR0_ARM.bin

Everything went well. This device, after flashing, is reporting a version of 21.2011.38-1.

Then I realized my other N900 is reporting a version of 21.2011.38-1.002.

I figured I would check to see if such a file exists, and sure enough, there is a file at http://nds2.fds-fire.nokia.com/fdp/i...ED_MR0_ARM.bin

I ran a diff, and the files are different.

Then I started trying higher version numbers, and there is a bunch of them. For example, at http://nds2.fds-fire.nokia.com/fdp/i...ED_MR0_ARM.bin

What is this? I have no idea. Did the Nokia engineers continue working on future updates behind Elop's infamous back? Could there be some goodies in there like Flash 11 and other insanity?

I have no idea. But if you decide to flash any of these, beware. I can confirm the first image seems to work because I just flashed my phone with it. As for the other ones, I don't even know what they are. It's interesting though.