Saw something odd today. I had may party rogue in a room alone (everyone else in the corridor), while opening chests. Every successful disable device or open lock gave the experience to Serena outside the room. Note that Serena is rogue 7/ranger1 and my primary rogue is rogue5/ranger5
Odd... Can you confirm that this is repeatable? I.e. some other place, room.. It may be they took a shortcut.. I.e. Saying "Who would take 2 rogues, and then use the lesser one to open the chests... Lets just give the open/disable XP to the best rogue in the group." Something to look into definately.
XP is given to the entire party for disarming & opening, isn't it? If so, perhaps the PCs are too high level to warrant any XPs, while Serena is low enough to get some, just as can happen when a mixed level party fights low level monsters.