I had the same problem on my 99 m750. I'm now very careful when I have the tank up on the hing to make sure it is not tweaking it. I got it fixed with an epoxy resign something or other at my local shop in Santa Cruz when I lived up there. I never had a problem after that. It was only like $150 materials and labor, probably could have done it myself fo a lot less but.... I can't remember what the material was though.