When I am done using the phone (S3) I've always pressed the right bottom (Power / Lock) so that the screen will blank out.
Now, since the 4.3 upgrade, when I push the right hand Power/Lock button, 1/2 of the time, it brings up the VOLUME control.
This is a real pain, and I do not see a way to disable.
Please advise, this is very fustrating.