Croesus
Adventurer
Under no circumstances can a character gain additional experience points by any means until he or she actually acquires the higher level through the required training/study course. Thus, a character who successfully adventures and gains experience points which not only equal a new level but are almost sufficient to gain yet a second such level, cannot opt to forego the period of training and study necessary to go up a level in favor of gaining a few more points and training and studying for two levels at once.
While not stated explicitly, I stand by my earlier answer that the character can receive a very large XP award, but only up to 1 point shy of the level beyond the one they are gaining.
The clear implication by the first bolded passage is that a character receives all the XP, even the points that are above the threshold for his new level. The clearly stated point of the second bolded passage is that once the character's XP are over the threshold needed for a new level, no new XP awards occur until the character trains.
My reading of the rules is:
-A character can receive XP awards so long as the character is short the number of XP needed to reach a new level.
-Once the character is over the threshold for the new level, they stop receiving XP awards until they train.
-The XP award that pushes the character over the threshold can push the character over the minimum XP needed for that new level.
-The XP award that pushes the character over the threshold cannot be enough to allow the character to gain more than a single new level.