I think the kinds of situations clark411 mentioned are times when it might be permissible to give the rogue the exp, or at least give him more of the exp than everyone else gets. The party's not backing him up much there. But as a perfect example of when everyone splits it normally:
RoguePC: I search for traps. (Roll). I got a 23.
DM: You find a strange copper plate on the wall. Just getting near enough to see it clearly causes your skin to tingle and your hair to tingle slightly.
RoguePC: "Okay guys. It looks like a lightning trap. Everybody get ready."
WizardPC: I cast Protection from Elements(elec) on RoguePC.
ClericPC: I get out a potion of Cure Moderate Wounds in case he really takes it badly.
FighterPC: I draw my weapons and move to the back of the group with the other torch, taking 20 on a spot back the way we came, in case this is an ambush.
Whether the rogue succeeds at the disarm or not, everybody did their part there. Everyone gets their XP. On the other hand if a Half-Orc Barbarian in my campaign tossed the halfling down the hallway to "look" for traps, I'd give the rogue most of the XP for any he dealt with, but I'd give the Half-Orc a bit of bonus RP exp.
