Toyota Repair: a/c, aamaco, rotten egg

Question
I have a 2002 camry, 4 cyl. 20,000 miles  Recently, when the a/c is turned on it has a horrible smell, some say it smells like rotten egg like or sulpher. I think its more like decaying flesh.  Yesterday, I was told by my local dealer that he has had a lot of complaints and that Toyota said it was due to the gas used and then later told me my filter was dirty and the smell would go away once I changed the filter.  The filter was changed, but the smell remains, althogh less than it was before. I use BP/Aamaco, Sunoco, Hess generally. Could it be the gas?  If so, what should be used? If not, what could it be. Thanks.  

Answer
Toyota has issued a service bulletin(EGOO3-03)regarding sulfur smell, baiscally saying that sulfur is a natural component of crude oil from which gasoline is refined and the amount of sulfur can be decreased yjrough the refining process. The amount of sulfurin fuel sold in california is regulated, some gas sold in other states can have"substantially higher sulfur content" the content may also vary between brands and locations.
Unless the check engine light is on there is no other solution for the problem, my personal advice is to try using different brands of fuel, try union 76 if available.