Hi Mario,
I noticed no one had answered and this may not be the answer you are looking for, but here goes anyway... (I'm kinda new to posting in the forums, but have been a member 3 years)
So, for at least 2 years, I've been using "Easy Screenshot" by LoveKara from the Play Store. It doesn't take a lot of memory, it works perfectly and all my friends use it, since I've recommended it. I didn't know the Galaxy had it's own Screen Shot, if it does, and with this app, there are no ads, not a bunch of bothersome junk like "New Apps Here!" on extra screens. You just push the home button and power button at the exact same time and you have your screenshot! It even gives you options on where to save them in settings when you first download it, and yhe app never bothers you again. FIVE STARS for sure!
I hope this helps, but I can understand completely if you don't want to add another app to your phone...
Peace!
Pamela Michel
"Imma Google Girl in a Google World!"