installed this valve, PL8950, exactly to instructions...installed trim parts, handle etc, let 'er rip, and two problems: most annoying one is that i either get all hot, OR all cold, not a selectable mix of the two. possibly related is the red safety button locks out from the temp numbers on the small trim ring getting lower.. i.e., it's as if the safety is to prevent you from making the water any colder.. obviously, that is not the point, and clearly something is 'running' in reverse.. problem 1) when rotating the temp valve handle from max left to max right, at about the 8 0'clock position, there's a barely noticeable flicker in the stream from the showerhead as it switches from all hot to all cold problem 2) rotating the handle counter-clockwise, the stop button 'locks' the valve from being turned further counterclockwise, which is in the direction that brings in all cold water...turning the valve clockwise, i.e., placing the handle towards the max 9 o'clock position, corresponds to LOWER temp numbers on the small dial/trim ring as i turn it to all HOT water....?!?! any help from the pros? i've installed this for my girl's brother, he bought it as a closeout display model with no instructions, i've been using the pdf files off the mfg website.. i've talked to HB awhile ago, and they told me basically if there's a cartridge problem, i'm screwed, because while they normally send out replacement parts, this one is their high end 450 buck cartridge, they won't... the 'backwards' temp conrol, i can deal with.. i'm sure i have some cam reversed, etc... but i should be able to rotate a valve and decide how much of each temp of water i get, right??!?!