On 2008-07-06, B A R R Y wrote:
You've NEVER had the bar slip past the next (or all the way to the
floor) notches? You know, your finger has a touch of pressure on the
button?

Why are you keeping the button depressed?
Keeping the button depressed does nothing after releasing the catch
except preventing the catch from re-engaging at a stop.
Press and release.
Move your thumb off the button and place it atop to your index finger.