@henryroomba , Lou, If Roomba does not return to the Home Base once a cleaning cycle is complete use the trouble shooting 1st link below to aid in fixing the fault. 2nd link is a forum that discuss the same issue you are experiencing and may be able to shed some light on it for you. Good luck.
I hope this helped you out, if so let me know by pressing the helpful button.
http://uksupport.irobot.com/app/answers/detail/a_id/8373/kw/not%20returning%20to%20home%20base
http://irobot.hivelive.com/posts/c2796c87a8