I'm getting the same error Vecter. Did you find a workaround? Thank you for your time.
Cheers,
Enthar
EDIT: I disabled the addon Bagon and no error. Try this if you get this error.
Sure i already updated ace I'll do it again then
For the mount bug if you point me in the right direction I should be able to fix this for you (and send you a pull request). Even without Jamba Mount loaded though I still have the issue on my Pally team, but the only Dismount() call I could find is in that module.
Quick question - Can the mount behavior be replicated with battle pets - i.e, I summon a pet on my main and all the followers summon the same pet?