
Jeremy Mac Donald |

Unless something about the plane itself is getting in the way this ability works fine on any plane. Does not matter if it is a spell like ability, actual spell or a scroll or some such. Anyone can use teleport (and, by extension, greater teleport)to move around on any plane.
Can't use teleport to move between planes however. For that you'll have to find a different mode of transport.
Nothing about the outsider type is granting one any form of teleport. If the outsider your looking at happens to have greater teleport thats all well and good for it but it does not get this ability because it is an outsider, it gets it because X creature happens to have greater teleport as a spell like ability. Being an outsider does not effect the abilities or function of greater teleport in any manner - works the same for them as it does for everyone else.

Jeremy Mac Donald |

The outsiders are Devils and have it in their description, so they are set to teleport anywhere on their current plane.
Oxi
I'm not sure if we are miscommunicating or not. If the Devil you looking at is one of the ones that happens to have teleport or greater teleport (only some of them do, Lemures certianly don't) then, sure, he can teleport around the plane just like anyone else that happens to have greater teleport as a spell like ability or, indeed, just like any human wizard can teleport around the plane he is on so long as he has chosen to memorize greater teleport for the day (or is using a scroll or some such).
Greater teleport works the same for everyone - its an equal opportunity spell. Some outsiders are lucky in that they happen to have it usable at will but it works for them just like it works for everyone else - they are just likely to use it more often (Why walk when you can teleport every where? Heck why even bother with legs).

Oxiplegatz |

Heh, got a bit confusing there. But the devils who the players will encounter is a Gelugon and probably a couple of wandering Orthon's (FCII)and they have greater teleport at will. So they are free to tp(k) around in the dungeon the players are about to enter. But to not make it too hard they don't want to be chickens and tp back to the gelugon, they sure wanna try kill the intruders and score some advancement points.
And just to mention it, the Legion Devils and Steel Devils are very cool.
Oxi