jQuery version support

jQuery version support

The company I work for is fairly conservative to the utilization of open-source software due to not having the same "support blame" model that the big-house shops do when utilizing their software (IBM, etc). I was able to bring in jQuery for our company a few years ago, but having trouble selling the need to stay up-to-date on releases (due to upgrade/testing effort involved).
 
How would you describe the support model to management in relating to the statement "v. 1.4.2 should be upgraded to the latest (or newer) version due to v. 1.4.2 no longer being supported by the community" (not sure if this statement is true, but just an example)?
 
Really strugging getting past the "if it's not broke don't fix it" dilemma and was wondering if any supporters of jQuery could provide any ammunition to not utilize older versions and invest the time to upgrade from purely a support perspective if there is ever a problem?