Pentax AF Zoom Question

I have had a Pentax K-x DSLR since it came out. It came with the standard 18-55 DA lens. I just got a 50-200 4-5.6 DA lens. With the 18-55, when the camera is set for AF, you can't turn the focusing ring manually. The 50-200 focuses with AF properly but when AF is set, the focusing ring can still be turned manually. Is this normal for the 50-200?

This is from the B&H description (I think it's the same lens) -
'This DA 50-200mm zoom features a responsive "Quick-Shift Focus System" that allows photographers to instantly switch the focus mode from auto to manual with a slight twist of the focus ring."
That line is not in the description for the 18-55mm.