KM doesn't remember window position, I've set the window size to 891 px w & 718 px h, my laptop screen is 14", and I don't know how to position the window.
Try this to get your information on the window. Position the window where you wish to be when starting. Use EDIT - CONFIGURATION - BROWSER CONFIGURATION to open your configuration and put 'display' in the filter line. Look for kmeleon.display.XPos and kmeleon.display.YPos to get the values for top left. The values for kmeleon.display.height and kmeleon.display.width can also be found there.