I think this is related to my issue here:

http://feedback.arma3.com/view.php?id=11582

Sort of but this is separate software.

Same problems here.
I think thomsonb is right, cause when i turn off TrackIR in the "controller" menu i get the same issues when trying to look around in "Free Look".

Seems to be something wrong with the "view".

I get the same but when I run backup turn I make left turns real fast

yep.. trackir is now broken :(

Confirmed, Track IR is now broken. I thought it was because I updated my joystick driver today, so I did a fresh reinstall of Arma3 Beta. It worked fine directly after install, but returned with the most recent update. Now if I slightly move my head to look around instead infantry movement will move in the opposite direction but greatly amplified, eventually spinning rapidly. It makes playing infantry impossible now.

I am suffering from this same thing. Day before yesterday, it worked fine. Yesterday TrackIR began to conflict with movement resulting in the char. spinning and making play impossible unless the TrackIR was paused or disabled. Nothing on my PC was changed between those two days.

Track IR does seem to turn the head, but it is also turning the body in the exact opposite direction, so it appears not to work.

Usage of TrackIR in vehicles works fine since the character vehicle cannot pivot in those scenarios, so those using it for aircraft only shouldn't see a problem.

Same thing with me (#0011617). Started the update before todays. Checked drivers, toyed with TrackIR settings, and no joy.

Just made the same report with exact same issue. In order to use Track IR I go back to the non dev beta

FIXED - Can a moderator or someone with the power close it?

Latest Download and it is working correctly again.

It is true, thanks for confirming the fix even before I was able to announce it ;)

And thanks a lot for helping us improve the game!

Mass close.