Do animation rotations refuse to accept negative values?

I’m trying to make my character’s head turn left.

But the animation tool insists in automatically autocorrecting negative values to positive ones, so -20 degrees becomes 340 degrees, meaning the character does a full headspin instead.

i have come into this problem before, try this:

i take it you are using the rotation tool ( can’t think of it’s actual name ) when this takes place.

instead of doing it with the tool, manually use the transform settings to make that animation frame.

typing in the -20 opposed to using the rotation tool.

hope that was some type of help.

The problem is in Unity 5.3.5f1, the previous version(5.3.4f1) works well. I’ve tried to install that one and it works.
Cheers