I have read
all your other posts not just on this thread but on all the forums.
You have
not told us what your trigger_changelevel settings are or how your landmarks settings are configured.... You have only told us that they are where they should be, and named the same.
Since you didn't understand the basic concept of two trigger_changelevels, I thought that you might not have the rest set up correctly.
I guessed that you had not changed maps at all because the Gman was only in one map, so you might have gone back to map 1.
(mad but logical). The only other cause for this is testing in GOD mode, entities sometimes follow if the trigger to spawn something is happening when the level change is triggered. Either that or the Gman was actually in the trigger area?
Most of the forum posts you make deal with CS.
It would be silly to ask if you are trying to place a level change in CS,
wouldn't it !! ?After all, you are an "experienced mapper".........
Which makes me wonder why you are having trouble with this in the first place.
If all else fails try reading
Complex Level Changes at Collective.