I am replacing my old shower enclosure with a Merlyn M Box 900 quadrant, the tray is level, but after assembling the frame with fixed glass panels fitted and trying it on the tray to position the wall profiles on the wall, i have to flex the frame to get the wall profile level with the spirit level, (is this a normal occurance) I was just worried that it might effect the smooth running of the doors when i fit them. 