About the whole 'not getting my achievement when I should' deal.

I've heard some complaints with not getting a campaign achievement (this happened to me with 'mercy killer') and with not getting the expert achievement. After some digging around, I found out that you can fix this by just voting for a restart campaign once everyone is there, at the beginning. The problem was that some people would miss part of, or all of, the beginning movie. Which counts as you joining late and not being qualified for that achievement you want.

So rule of thumb? If your after something; restart the campaign as soon as everyone joins.

How about Venom having to take out 2 Tanks to get Man vs Tank. He can't even catch a break in the virtual world. Yeah, it seems there are many small issues affecting the game, hopefully valve is taking the necessary steps to patch them up.