If it was a stereo-sampled sound, the pan is actually a balance adjust, which means you're turning down the opposite side when you "pan" the sample. (like on a car stereo) Therefor, if a snare was panned left in the original mix and sampled stereo, when you "pan" right the sound will simply muffle on the left and come out no louder on the right.
I don't know that this is your problem, but it's an idea. You don't need to set the record mixer changes option, in fact I recommend not doing it on your first pan, but whatever works for you.
-tank.
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Cuz you aint seen through my eyes
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