go ahead and continue to play Russian roulette....
From the source itself:
Should ketchup be refrigerated?
Because it is a very acidic product, ketchup does not spoil easily. Once opened, in order to maintain the product's quality more effectively, we do suggest that ketchup (and any other processed food) be refrigerated after opening because refrigeration retards spoilage.
http://www.heinz.com/Consumer_faq.aspx
Good God man...what more do you need?!?!?!?!?