I don't follow how this is possible.
Same Effect with Differing Results(PH pg172): "The same spell can sometimes produce varying effects if applied to the same recipient more than once. For example, a series of polymorph spells might turn a creature into a mouse, a lion, and then a snail. In this case, the last spell in the series trumps the others. None of the previous spells are actually removed or dispelled, but their effects become irrelevant while the final spell in the series is in effect."
I realize it discusses spells and not infusions, but infusions aren't core. It wouldn't be a stretch and say this rule would apply to anything whether its a spell, infusion, or psionic power. Only one infusion per item whether its a weapon, armor, or wand. I run my game that way in any event. When rules are overlooked things get out of hand, much like the psion who spends more PP than his manifester level.