Wow, thank you for that very comprehensive reply, +Tristan Anderson
! I have asked if there are any AD differences between this user and the others. And I've just recalled that sometimes if I pre-populate the control with a user that normally wouldn't behave that way, it does...hmmm. The first link made my head go splodey so I will start with the second I think :) Thank you very
much for taking the time to explain that to me, it's much appreciated.