Is it normal for an SD Card to increase in size?

I bought a 32 GB "Memory Stick Pro Duo" for my Sony PSP. In actuality, it was simply an adaptor for 2 MicroSD cards. Strangely, one MicroSD Card is in a dead state, and the other went from 16 GB to a whopping 29 GB. Is it even remotely normal for such a thing to happen?