Ya man, what you wanna search for is floppy mirror syndrome or FMS. Wits end has a solution for it. Basically there is a spring in the center arm of the mirror that is held down by a lock washer. In some cases that washer decides to find residence somewhere else and now you have no tension on the spring to hold the mirror in place. The way I solved this was a small double threaded pipe (I think 1/4in diameter which allowed the wires to pass through it and maybe a small dremel to smooth out the edges) passed through the bottom of the mirror washers/nuts to hold tension. Has been over a year and holding strong.