IIRC, Trancend doesn't produce the flash chips, or probably any interface chips, they just assemble parts from other manufacturers and put their name on it. With all the volatility in the flash markets lately, I'm sure the product internals change often. You've been very unlucky (and knowing the price of those cards, I'm bummed hearing about it), but I wouldn't write off transcend permanently. There are certainly differences in manufacturers though, sandisk didn't get to be where it is by accident.

-Jonathan