I setup another plugin (SimpleModal Login) that creates an overlay login box. I verified it worked correctly.
Installed, activated, connected JetPack, the SimpleModal jquery fails. Loads new page with only the quant tracking pixel.
Deactivated JetPack, functionality of original plugin returns.
I saw in a previous post Matt saying to contact JetPack to report problems. Posting here before hitting the firstname.lastname@example.org folks.