Subber10 over at The Crawfish Boxes touched on the banned stimulant that Meszaros, Fixler, and Cabral tested positive for: methylhexaneamine. WTF is that?
The infallible Wikipedia basically says that Methylhexanamine is a nasal decongestant, though it can be used as a general stimulant.
Back in 2009, five Jamaican athletes were suspended for testing positive for Methylhexanamine, but only because the anti-doping panel couldn't figure out if it was actually prohibited, so they suspended them anyway, because it was close enough to another banned substance.
This bodybuilding forum says that methylhexaneamine has properties similar to amphetamines and ephedrine.
So, to sum up: There's a pretty good chance that Meszaros, Fixler, and Cabral were busted for a nasal decongestant.
If I'm wrong - and it's entirely possible - leave a comment.