I just acquiered one and notices it was taking too long to clean the entire pool: 3m by 7m long. The cable coils up excesively. Read the trouble shooting and made sure all steps were covered, including amount of cord in pool, obstructions, clogged filter bag, bottom lid placement, and debris in track. The pool bottom is covered in sediment, so I can easily tell where the robot has been. It seems to be running in circles and does not cover the entire area. Any ideas?