I just noticed something odd.
Invites appear to be taking their "sender" information (e.g. so and so invited you to Geni...) from the user's current tree viewer - and not the actual user sending the invite.
For example - I recently invited about 6 relatives to my tree. However in the news feed and email updates, it says my mother's ex-husband (who doesn't even know the others exist) invited them.
What I think happened was that I was clicking around, clicked on my mother's ex-husband and that launched his tree as a new tab. Then while I was clicking around there, I must have invited the others - and that's the only explanation I can think of as to why the invites didn't come from me.
Hope this is making sense - the rest of them are probably creeped out by being invited by a complete stranger due to this bug, so I wanted to report it.