S*** I forgot again!
See, skwinty, a challenge must be validated by the poster before the solver can post a new one.
Else... You'll get a reprimand from LM! There must be order in this thread.
If one cannot monitor a challenge/hasn't one ready/must dash away, can declare an Open House, even before confirmation (the formula, in that case, is "OH if right"), but never can a challenge be posted before a confirmation.
If the poster is not online for a certain number of hours (12 I believe), an agreement can be reached among Ppruners to validate the challenge in absence of the original poster, but this happens in exceptional cases and it must be evident that the guess is correct.