I love my rev 5 still, no problems.
My buddys though, his 6.3, when on in his car keeps going off. Its like it is instant on on K band, then Switched to Ka, goes full, Back to K, and Ka and such. Then, other times it stays silent..
Time to send in? and anything we can do. Plugged it in my car and it did the same thing. And I reset it twice.