I've played 3.5 in five different states with eight different groups and everytime I've ran across this:
Me: "I cast detect magic/evil/good/etc"
DM: "The overwhelming aura blinds/stuns/dazes/makes your head explode."
I've literally seen this happen across the USA, again and again with groups that have had no contact with each other.
I like the detection spells but the idea that an aura is "overwhelming" and therefore must do something to someone that can see it needs clarified. Either the rules need to have something where this does or doesn't happen.
On a related note:
What do auras do? I mean really you gain no benefit from having one and all it does is make you a target for those who can detect them. Can we get some benefit/ penalty thing going on for auras? Or make them into something that has an effect?