If you check a thread I posted just last weekend titled "Grey tank is fixed. Links to HOWTO...." you will see my description of how I fixed my grey tank. Exact same symptoms as yours. I still need to post my pictures.
Short description: I did plastic welding to take care of it. I've copied the links I found during my research on how to do plastic welding.
http://www.stanmech.com/HowToWeldPlastics.htm
http://www.plasticweldingschool.org/...in-welding.php
http://www.plasticsmag.com/welding.a...pr-01&aid=3212
I found that Harbor Freight had a hot air plastic welder on sale for $30 plus I got an extra set of welding rod for $5. I have a Harbor Freight retail store just two blocks from where I work. I already had a small air compressor that is required to operate this welder.
I'm a second owner with no extended warranty.
I was able to do the fix for a lot less $$$ and time than taking to a dealer.
All the same I'm glad mine was grey instead of black
If you have it done, be nice to the tech and sanitize the black tank well.....
Eric