Map Problems

[Zan]

Can someone pleaseexplain to me why supposedly impassable tiles randomly convert themselves to passable tiles on my map, and how to fix it?
It's not all instances of the tiles, in fact it seems to be area-based if anything.  Every tile in the upper-upper right corner of a city map converted itself to passable, and every wall tile in a house map.
(holds a very large handgun to RM2K3's (hypothetical) head)
Help, before I do something I might possibly regret much, MUCH later...but which would sure as hell be satisfying right now...

[Blizzard]

Read under "My chars can pass over impassable stuff."
http://rmrk.net/index.php/topic,6835.0.html
It should apply to RM2k3 as well.

[Zan]

Read under "My chars can pass over impassable stuff."
http://rmrk.net/index.php/topic,6835.0.html
It should apply to RM2k3 as well.

Yeah, no, I checked my passability and stuff in the database, and the tiles work perfectly fine in most places.  Just not in the ones I mentioned. I could set events on everythiing I want impassable, but I really don't want to do that.

[darkelementwars]

check all the layers and make sure they're nothing on any higher/lower layer that may be acting as a bridge and allowing them to pass over the impassible tiles.