The real question is: how does it sound to you? That receiver has Audessey, are you saying you ran it and it set the mains to large? If you run it 3 times in a row you may get different results, so it isn't perfect. It is easy enough to set them to small manually and run it again. It can be that your sub is not handling the lows well enough OR the sub isn't adjusted correctly. What are the volume, x-over and phase set to on the sub? Phase typically should be 0; x-over set to its highest point or bypassed, and for the first calibration, start with the sub at 50% volume to see what Audessey does with it - if Audessey cuts the sub's level by a lot, it is set too high. If it is adding too much to it, it is set too low - adjust to get it to a smaller adjustment from 0 if you can.
Sub looks to be the weak point for sure. Yes, you can keep the mains large, but that won't necessarily help the sub. That sub is only rated to 28Hz, which isn't quite going to deliver for a good movie experience IMO.