I've heard this one before. It's not me, it's Melee. If it's a perfect 90 degree angle, it happens. Sorry.There seems to be an issue with ledges on a few of these stages, Milun. When playing as Captain Falcon, pressing away from the ledge while hanging will make him do an instant walljump instead of the usual drop. This happens on the right ledge of the B+/PM Temple, both ledges of the two platform Yoshi 64 stage, and both ledges of the new Fourside.
This only happens with Falcon. No other walljumpers have the problem.
Now, as for the other stages: I will get to them... but unfortunately, not soon. It's once again the start of my uni, so Melee takes a back seat until then.
Sorry guys.