there are several 'fixes' posted, but all (other than tightening the TV cable) require fiddling with the valve body.
Swapping to a different valve body or reinstalling the ModTV Up spring (I think thats the one) are the 2 fixes that supposedly work. I have not tried either.
Mine does it and it, and I don't like it.... But I just avoid driving in the range where it happens.
Bob