So, a few times at the range, I'd be shooting my CZ 75C, I'd pull the trigger and the trigger wouldn't pull.  I'd pull extra hard and it would go off.  I couldn't figure-out what the problem was until today, when I was at an outdoor range.  The same thing happened and I realized that while shooting I'd inadvertently pushed the safety lever up just enough to engage it.  The red dot was still about 75% visible.

Is this something other CZ users have encountered?

Regardless, it's user error and I realize I need to modify my technique.  Any recommendations?  I'm pretty good keeping my thumbs stacked properly as I've been shown (i.e. not overlapping them in any way).

Thanks in advance to you fellow CZ shooters.  I love this gun!

BTW –– First time at an outdoor range and I was magically shielded from any and all brass hitting my head and face.  I guess that question has been answered.

Not that this helps you much, but yes I have the same problem . . . with my CZ-52!

My right thumb just keeps pushing the safety up, so about once each mag it won't fire and I have to push the safety lever back down.  It gets pretty irritating.  

From the sound of it you are shooting with your thumb either under the safety or right next to it and when your shooting you engage the safety. Try putting your thumb on top of the safety when shooting and that shouldn't happen.

My thumb actually goes overtop of the safety by quite a margin.

Do you have small-ish hands?  What grips are you running?

Seems like a strange problem to me. I have small hands and my thumb is half an inch below the safety when I shoot. Perhaps I'm not using proper grip techniques though. I let the tip of my thumb rest on top of my middle finger - well below the safety. If anything, it sounds like you have rather large hands.

I fire all of my CZ pistols with my strong hand thumb resting on top of the safety, just like a 1911. Do that, and I think you'll find you'll be more consistent, and of course you will never have this problem again. You'll also control the recoil better with the higher grip.

And in the "safety vs. decocker" discussions that pop up here every now and then, you can join those of us that say it would be impossible for us to "forget" to release the safety on our safety equipped models.

Thanks.  I'll have to modify my grip if the problem persists.  My strong hand thumb usually rests underneath the safety after switching it off.

Try shooting thumbs forward (click the combat grip link in the 1911 section) with your thumb riding the safety.