Mac + Sansa Express + 8gb MicroSD = DOOM!?

So, I thoght about using my sansa again as a thumb drive for the Macs at school. I plugged it into the mac (with my 8gb card) and it only showed the internal memory. Thinking it was weird, I pressed eject (btw, only one drive appeared) and pulled out my SE. But for some reason, the music will not show up on my sansa (it was on my 8gb microSD btw) and when it refreshes the database, I go to the settings, but the microSD will not show up. So yeah, did it delete my music, corrupt my card, or what?