When you attempt to hide, do you attempt to hide in every room, or do you have to attempt to hide in -every- room you move into?
The quick answer is you do not have to hide in every room but note that the help file says:
"Staying hidden while moving requires strong stealth abilities."
So that can be a contributing factor!
My second character was sneaky. I remember asking this question myself. If I remember right, the answer is; "If you're hidden and you successfully sneak, you remain hidden in the next room."
Low level hide/sneak means you unstealth even while sneaking. Treat them like two completely different skills that don't touch.
High level means you are a ninja.
Ah. Thank you!