side switches on 70-200 stick up too much?

I had a 1 year old 70-200 f/4 IS that I sold and replaced with a several-year-old f/2.8 IS model. While using that lens, I find it frequently quits auto focusing because I've hit the switch with my hand just by holding the lens. The AF and IS switches stick up a bit from the lens body where they were flush on my f/4 IS version. Are the new f/2.8 IS lenses using flush switches or is it just the f/4 lenses that use flush switches?

My f/2.8 IS is about two years old now and I'm really not sure how much they stick out. It's never been an issue for me. Typically though when I am supporting the lens with my left hand, I am holding the bottom of the tripod ring. I never get near the switches.

My f/2.8 IS was purchased in 2006, and the buttons are flush.

Mine has a US date code. From memory, I think that means 2005. Maybe there was a switch? Maybe starting with UT date codes?