events.dat is somewhat unreliable. As an example, it might be necessary severe
walks to and fro the map label on level 31 in order to close Open Sesame quest.

Please, send a savegame, with Tux near the map label, before to trigger it.
It will be easier to debug and fix.

Attach a savegame. Do you need the backups too, from before crossing the gate? :>

the backup, no, but I need the .sav.gz !

sorry, I did not see that you already attached it.

I managed to find more or less the place of the bug.

I've changed the event code to:

	print(cmp_obstacle_state("HF-Gate-inner", "opened"))
	print(cmp_obstacle_state("HF-Gate-outer", "opened"))
	print(has_quest("Open Sesame"))
	print(done_quest("Open Sesame"))
	if ((cmp_obstacle_state("HF-Gate-inner", "opened")) and
		(cmp_obstacle_state("HF-Gate-outer", "opened")) and
		(has_quest("Open Sesame")) and
		(not done_quest("Open Sesame"))) then
			end_quest("Open Sesame", _"I found the gates. The firmware server should lay
beyond them.")
	end

The values printed to terminal were:
true
-> false
true
false

Needless to say, using these savefiles (or not), both gates were open.
Lua syntax also seems to be correct, so the problem is not on events.dat, but at
cmp_obstacle_state.

Therefore, updating the title. (I've did a few debug printfs on the C part of
the code which handles positional events and none of them failed)
I've tested about Spencer's Death but found no bug there, Spencer death will
only trigger an event at Town but this is Game Design fault (that killing him at
level 59 does nothing)

Linking possibly related issue 824.
While not directly connected, both are about identification problems at the same
place (except one ended with a crash, and another one ended with an event not
triggering)

There is a possibility the bug is related to the obstacles itself and I'm not
looking at the right place (as in: cmp_obstacle_state may be innocent), so I'm
linking both issues for further analysis and study.