Another thing about 'pre-B' pistols is that the mags don't drop free (European practice). The adjustment Walt mentioned should take care of that if necessary.
Until recently, they didn't drop free in most CZ models.
The solution is to replace the mag brake (a flat piece of metal that covers the mainspring [also called the hammer spring] and presses against the mag) with a flat one from the 85 Combat. Many of the newer models, at least when imported to the US, have this already done.
Or, even more simply, remove the grips and take the top of the existing mag brake loose (it's held by a pin) and bend it so that it is bowed the other way (against the mainspring/hammer spring), reinstall the pin, and you're good to go.
It's generally an easy fix but the metal is pretty stiff and brittle, so be careful when you bend.