Here in the USA, there has been a rash of bikes with plastic tanks (pretty much all models beginning in 2006, and the S2R in 2005) that are having a problem with the fuel tank swelling.
There are three main symptoms: front pressing against the keyswitch, frame bumpers no longer sit on the frame (are sitting outside the frame or are on the way), and rippling or "waves" in the sides of the tanks.
Ducati (North America) has been replacing the tanks on a one-by-one basis, there has not been enough reports of them to be a recall yet.
The main hypothesis is that the ethanol additive in USA gasoline is the culprit (in almost every state in the US, gasoline is 10% ethanol, commonly called E10). This is not the E85 stuff coming down the pike, but it has been an octane additive for the last 5-10 years. My understanding is that ethanol is not used as a petrol additive in the UK or Europe and I (we) believe that Ducati did not make the tanks on these bikes E10/ethanol-proof.
If you guys are going to be getting ethanol added to your gasoline, you might want to look into getting your tank lined first with something ethanol-proof.
Here are some photos (None are mine, these are collected from a local website)
Bike one: S2R http://kuixihe.com/zenphoto/zp-core/...l-photography/
Bike two: S2R
Area on tank where the key/latch area has rubber through the paint and is now rubbing through the tank:
Right side ripples and bubbles. Oddly there are no ripples on the left side:
Right side ripples II:
Right side bumper:
Left side bumper:
Cracks/blisters around filler:
Bump on tank: