Unity ignoring script modifications (and scenes mod) (uses old version source)

I have one single scene with one single gameobject and a single script component tied to it, when i launch the scene, unity uses the previous version of the script, ignoring all the modifications i've done, (commenting it out completly or adding logic is disregarded) i don't know how to modify that old source, because when asking to edit the script tied to the gameobject it brings me to the new version in monodevelop and still uses the old version at runtime. maybe a simple issue, but cant figure it out. What can i do? must be so simple...

Edit : the same seems to be happening for the entire project, including scenes. when i launch the game it just uses old project data.