I first noticed it about a year ago – the ease with which the rear mudguard scratched. Then the flaking started, it was as though the plastic was turning to powder, all very unsightly! So I ordered a new one last May (2012) – AP8126706. It finally arrived in the UK about a month ago!
A quick internet search on UV damage to plastics proved quite interesting. It seems that they add the plastics equivalent to sun-cream or sun-block to the mixture before it’s injection moulded and this converts UV to heat rather than causing the plastic to decompose. Maybe Aprilia skimped on the Factor 50 when they moulded mine! 😀