I can't say when it started, but after reseting the dialogs my "z" works fine again :D, and I knew it was not my keyboard 'cause of two reasons:
1. I'm on my new laptop, it's been on use barely for six months, it couldn't be broken, I take real good care of her and of all my stuff.
2. "Z" and "z" worked fine on the rest of my software, so the problem was with Construct, and it only happened with "z", "Z" worked just fine.
Anyway, it's fine now, if only I knew what caused it... I'm sorry I can't be of help... but at least you know it happens... and by the way, it wasn't the capx, I tried with different projects and the problem persisted.
Thanks for all the help! Terrato2012-02-28 21:19:03