Also, watch you dont use TOO many adaptors.
I know it's not the case, but say you were using an SCA drive, converted to 68-pin, then converted to 50-pin at the card connector end - too many conversions and you start getting signal errors... for all intents and purposes there's no limitation - general consensus is if it works, great, but dont design a solution that uses lots of conversions.
Just my .02