What version of CoD4 to play?

I just recently got back into cod4. Playing release version I had no trouble finding plenty of servers to play on including several headquarters normal and hardcore. Then I updated all the way to 1.7 which I think is the most up to date patch. I basically really wanted to try out the new maps.

But now at 1.7 my server options are severly limited and without any HQs gametypes and if I do find a HQ game hardly anyone is on the server or it was just a random.

So I'm wondering if mabey 1.7 isn't the latest patch or is everyone playing previous versions?

Also, after patching I get the keycode in use error everytime I leave a game early. I have to wait 10-30mins to join another game. Before I patched I could jump in and out of games without a single error.