Mine is about the same age and I have not had a problem either. Do we think the newer bags are being made more cheaply or something?
possibly. because I do not exaggerate - this bag could not be any less babied. it sits on the ground, it sits in the sand, it gets smooshed into lockers, it carries gigantor law textbooks, my laptop.. gym crap.. I don't baby my bags in general but this one I particularly relegated to workhorse status simply because of its size and foldability etc.. thinking it would get grimey.
alas, no. it's still very white.. no yellowing. as another poster said of course it's not as crisp as the day I got it but certainly isn't cracked or anything. just a bit worn and loved, but otherwise in excellent condition. not even dirt marks or worn paint which shocks me. I actually post about it often even in other subforums because specifically my mom made such a fuss about the cost of this bag compared to its relative lack of substantial feeling (and of course it being white and she felt, ridiculous) - when she bought it for me for christmas one year .. and years later she and I both marvel at how it's held up better than any luxury bag I've purchased. apart from maybe my chanel jumbo. which is basically an indestructible torpedo. another testament of past high(est) quality compared to its newer goods.