Animator Trigger gets stuck

Hello,
I’m using animator trigger called “land” that triggers when player is close to the ground. lately on unity 4.51 I started encountering this weird problem when the transition would happen before code called on trigger.
than I noticed that this trigger gets “Stuck”, that is after it is fired it stays on sometimes. I can see in animator windows that it is set to true like a boolean would and does not reset itself after use.
is there a known bug in unity like this? hopefully with some solutions?
Thanks in advance

animator controller > click on state > uncheck “write defaults”

I did this to all states in my animation controller. It worked for me.