First, see if I understand the situation: you pull the trigger, the gun fires, it cycles normally (the old shell is ejected, a new round is chambered), but the hammer is down rather than up, so you need to either cock it manually and fire, or fire double-action.
If you search for either "single" or "double" in this subforum, you'll find this is a really common problem....
Is this new behavior since a disassembly (or is the pistol new to you so you don't know if it's been doing it since disassembly)?
The most common cause of this seems to be someone disassembling and reassembling the pistol, and not getting the sear spring installed correctly in the auto safety. The procedure for that part of the assembly is also on Sailor Curt's site, but on Page 7.
http://sailorcurt.com/2009/01/cz-82-gunsmithing-part-7.html/ My experience has been that absolutely the only way to do it is with a jeweler's screwdriver small enough to fit through the hole in the auto safety (that description will make sense after you've looked at the good captain's site) with just a tiny notch in the screwdriver blade to catch the spring. You can buy the cheapest Chinese screwdriver set available at Harbor Freight for this, and it'll pretty much last for a lifetime of disassembly/reassembly.
If that isn't it, a worn sear seems to be the next place to look.
