I'm in the Eesti Life Catalog adventure, and Mr Hairball's dialog box says "No Verb Tooltip". (It also has the option to talk to him, so it's not a bug that makes this nonfunctional, it's just probably something that needs cleaning up.)
I don't see this any longer so I think it's probably fixed, but if you see it again or if anyone else does can you please take a screenshot or let me know what verb didn't have a tooltip?