After many years I opened my last saved game in SoU. I'm at the Temple of the Winds in the second level. I've cleared everything but I still can't open the door to the next level. My guess is I missed one of the levers.
However I'm not sure what happens if I move a lever twice. Will it become locked again? Can I tell which lever I missed by looking at it?
For example, next to the east lever there are 3 other "stuck" levers. Should the unstuck lever have the opposite orientation?
So I went ahead and figured it out the hard way.
... if I move a lever twice. Will it become locked again?
Seems that they would in fact become locked again.
Apparently all levers must be pushed towards the front (that is, towards the wall they're next to). Which means their position is not dictated relative to the other ghost levers.
Those ghost levers (the ones called "stuck" in the OP) are actually a reflection of the other 3 levers.
Can I tell which lever I missed by looking at it?
Yes, by looking at the 4 levers you can figure out which lever you missed. From left to right the levers are:
