On a completely unrelated note. People always say that in 3e, the caster could overshadow everybody in and out of combat, but i disagree. The caster must balance his spell selection. The caster is the only character that's utility is inversely proportional to its combat capability. if the caster wants to be a master out of combat, solving all of the traps and puzzles through a combination of intellect and arcane power, then in the fight the wicaster will not have many spells to bring to bear.
IME, this issue is most apparent when you have a memorization based caster (cleric, wizard, etc) who likes scribing scrolls. It applies to any caster, but spontaneous casters are a little more limited in that they have to buy scrolls to give them more options, which slows them down a bit in comparison to those with Scribe Scroll.
In the last 3.5 game I played in we had a wizard who, in addition to his daily complement of spells, wrote scrolls for every occasion. He actually solo'd a golem or two using some spell specifically designed to kill golems (I think it was called Ray of Deanimation, but it's been a while) because the rest of us were getting our butts kicked. IME, magic-immune golem encounters are supposed to be where the party saves the virtually useless mage, not the other way around.
I've heard a lot of people argue that it's balanced because he has to spend xp, but from what I've seen that isn't much of a deterrent. If you're following the RAW, the caster gets extra xp once he starts falling behind anyway. In that last 3.5 game, the DM actually didn't use that rule and it still didn't stop our wizard (until you start scribing high level spells, the cost is really quite negligible).
Admittedly, if the casters in your games don't bother with scrolls for whatever reason, this would not be an issue at all. When casters can't circumvent their daily allowance of magic (via scrolls/ wands/ staves) they can be much more effectively balanced around the concept of utility vs combat. With enough stored spells, however, their endurance becomes virtually that of the fighter with a flexibility and penchant for bending reality that non-casters simply don't possess (short of maybe a scroll-toting UMD guy at high levels, though he may as well be a caster at that point anyway).
YMMV.