I see you guys are using $.browser inside the infragistics.util.js but also reference modernizr, can modernizr not be used to do the browser detection?

If you are getting a Sizzle error with recent versions of jQuery, make sure your tooltipTemplate option can be interpreted either as a selector for a script block that has your template or is unambiguously an inline html fragment. If you are trying to provide some inline html try wrapping it in a span:

tooltipTemplate: '<span>test</span>'

if there is nothing in the template that is recognizable as html, we assume it is a selector to get the template text from elsewhere. More recent versions of Sizzle will throw an error if the selector is invalid, though.