I have an issue with Vex in the thieve's guild. She will no longer give any new quests. She seems to be stuck on a shill job, that's in my completed quests list, but which she doesn't think is finished. I've tried all the obvious things such as resetquest, setstage etc.. nothing seems to actually make vex believe that the job is finished.

Is there any set of console commands I can use to completely reset vex and / or the quest? Something obvious that I'm missing, perhaps?

I have never had a stuck quest that couldn't be fixed with setstage. Maybe try going around and talking to the other TG quest givers? Maybe you need to trade in a piece of armor with what's-her-name or report in with Mercer or Brynjolf (just throwing ideas out there). Sorry I can't be more help.