I will study more calm this noobtorial before posting.
I'm a CS6 pixel pusher too.
You should, for now, use the 'save for web' option instead of just 'save' so that you are sure you are at least using the png8 option and not the default png24 which can be a pixel killer.
Additionally, make sure all your setting are good to pixel including all tools. There is details of this in the noobtorial thread of the forum in the resource section. Review that to be safe ;)
If you use a stylus/tablet as I do you will need the settings for that adjusted too.
I set up a few profiles in CS6 so I can switch quickly between pixel and NPA work.
Any questions just ask or open a forum thread for feedback from more than just me.
I use Photoshop CS6 , I was saving in PNG without checking the color count correctly.
What app do you use?
You can always use that image specs its in the top menu.
I think it 's time to close the file I ended up saving a wrong way , I used the link you went and did a recount in 128 colors.
I don't quite know what's happening but most if not all of your pixelart submissions seem to have some problem in the way you output the files...or something.
This pixel uses 274 colors
http://akira.hopto.org/pj/?input=http%3A%2F%2Fpixeljoint.com%2Fpixelart%2F97053.htm
Managed to make the modifications , this now with 42 colors and no noise .