The required update for Team Fortress 2 has been released. Please run hldsupdatetool to receive it. The specific changes include:

- You can now duck twice in the air. Scout double jumps reset the in-air jump counts
- Increased the jump velocity to account for the tuned bounding box sizes. Jump height should now match the prior-to-last-update heights
- Added "tf_clamp_airducks" convar, set to 1 by default
- Setting it to 0 will remove all constraints on ducking while in the air. Useful for servers running RJ challenge maps.

Fixed HL2.exe hanging on shutdown

And from the Steam client update:
Finally... 90% of the time TF2 didn't close properly on my system after playing and I had to kill hl2.exe and the game overlay manually.

yeh, same here~

same here as well, think it was so for everybody. am i right?

I had it once ages ago, so not really