oPUHNANIo is probably right, do a quick search on how to clean them when they first come -- including the inside of the center post, which is often what gets people and machine oil likes to hide.
If not that, I generally associate a weird metallic taste with either a hot leg, intermittent short, being too close to the wall/floor of the atty, or under-wicking. Please report back.
*gives the horns*