I have a troubleshooting question.  Recently my Cleanview Helix has been much louder on the Bare Floor setting than on a setting closer to the High Carpet Setting.  I live in an apartment with mostly wood floors and I know that the louder noise is bothering my neighbors since we have thin walls, but by keeping the vacuum on a higher setting it's not as effective than on the lower setting.   I'm going to buy a new drive belt and hopefully that fixes the problem since my old belt is a bit worn.  Any advice?  Has anyone had the same issue?