We have the same problem. We tried a 1.5 " mattress topper that helped some but still not so good. Most people have better luck with the 3" topper. Now we are looking at an inflatable mattress hoping that it might workout better.
Jim & Kathy
Bailey, waiting at the Rainbow Bridge
Gracie, a rescued Beagle
2007 Chevy Tahoe
2008 FR Surveyor 233T