I now have 12.5 hours on my Fastrack 20/52. While mowing around a tree yesterday, a strange noise came from under the seat. Upon further investigation, I discovered the hydraulic drive belt slapping the frame? directly below the seat. It looks like either the belt stretched beyond the limits of the tensioner or the tensioner pulley spring has lost some of it's strength. The belt appears to be fine shape - no tears or strings. All the bearings and pulleys seem to be fine. It seems to make more noise making left turns and the left side tension pulley seems to flutter in lieu of being stable. Has anyone else had this problem? Any test or other places to look for a problem would be appreciated.