Oks here it is again lol.... I was having the same sort of problem with 2 of my windows, I dont know if they changed some code or somthing but just adding the one line "OnShow etc etc" used to work but now I had to add in "OnHide" and also the "Visible" tag.....
99.5% sure this will work
(Note I didnt say if that was -99.5 or +99.5 lmao)