Steam bug:
My coinhistory shows steamtrades, but the steamid associated with the trade is always 76561198008335925, which is my personal steam id.

Invite bug:
The 'invite' prompt in-game that shows up when someone invites you to a mission steals focus from the chatbox. On some older/slower machines (mine included) SK freezes just long enough for you not to notice this immediately if you're not looking directly at the chat box. While this is happening, I keep typing, and it clears out my input text when I hit 'r' and brings up all sorts of message boxes when I hit other hotkeys.

Search bug
Hitting 'esc' should be enough to take focus away from the search boxes in e.g. friends list, arsenal, etc. Currently, hitting esc does nothing, and there's no way to cancel the search to respond to something without using the mouse. Many people (myself included) do not use the mouse outside of missions.

Among other things, I've noticed lately that there are floating blocks in levels. Recently I also had some floating hearts, invisible vials, and invisible turrets. This usually shows up when I join a mission that's already in progress.

Floating blocks: 1, 2, and 3
Floating hearts