-1, There are a number of cases in jQuery where dynamically building parameters to send to jQuery functions works ALMOST all the time, but due to some kind of data exception, undefined ends up getting passed and jQuery behaves unexpectedly. (undefined as context or the second argument to attr, for instance). Historically, we have not special cased these situations, and I don't think we should start now, especially given the .on enhancement that will handle this problem generically.
