Cannot Invite Calendar IOS 6

Calendar Mavens,

Kerfuffled!

On my iPhone with IOS 6, Calendar includes "Invitees" while making a new calendar entry.

On my iPad, also with IOS 6, "Invitees" is NOT included while making a new calendar entry.

In both cases, the "source" calendar is attached to my GMail account.

In Settings | Cloud, both have "Calendar" turned ON.

There's only one thing I've found different between the iPhone & iPad settings: In Settings | Mail, Calendar, Contacts, the iPhone says "Exchange," and the iPad says "Gmail."

Any ideas or suggestions? After thrashing around for ~hour, I can't find a setting anywhere which resolves this issue.

Thanks!

Plane Wryter