It's a shame
I wasted more than 4 hours and didn't find a solution. I will never update anything related to Eclipse/Android
BTW, I tried to "delete the marker", ie went in Problems tab (can you see it? it's next to "console", "logcat", ..) expanded the problem, right click and choosed "Delete".
Then Eclipse stopped complaining about "aapt not found" (obviously, it's in place) but looooooooots of problem arouse: I cannot use the Launch button, nor the Run configuration menu, the eclipse log is full of errors, plus bonus refreshing external folder bug popping out again, and NPE throwed all over. Oh and -of course- if I manage to run a project, can see the logcat full of strange things like file not found, system executables not found, etc
Feeling so frustrated
Eclipse boasts to be the greatest developement platform in its market, but it's so bugged...