Are you seeing Magnesium in the list of nutrients with a milligram amount on it? If it is low it probably won't bother you. (like 50-60) or you could add a small amount of calcium carbonate to balance it out (about 2X the amount of calcium carbonate as the magnesium).
If you are just seeing Magnesium Stearate in the list of inert ingredients it never seems to be enough to actually count as a nutrient and is just one of the things they use in most pills to make them a pill.
I don't usually see people having a problem when it is just a little bit used to make the pill a pill and isn't on the list of how many mgs of which vitamin.
Twinlab seems to have one with out binders, but I can't tell if that also means no magnesium stearate
http://www.massvitam...-50-caps-1.html