I have the 16X memorycard from interac and it worked fine, untill about a month ago I started getting save errors. I noticed then, that the memory card was getting very warm. So I pulled it out right away, works ok along as it is cool, but when it warms up, 15min, it get unreliable. I am just happy I managed not to lose all my save games. I am now the proud owner of a 251 card, no problems.
Stay away from 3rd party hardware.