Won't recognize transflash memory cards

Today I went to a local mobile phone service in order to buy a transflash card. I had two transflash cards before and both of them got corruped for unknown reasons :S

They both stopped responding because of nothing, just simply got unreadable at one moment and I couldn't format them in any way. So, in the mobile service shop I tried two new MicroSD transflashes, one of 1 GB and the other of 512 MB and both of them were not recognized by the phone. The servicer said that that is due to a hardware or software problem and wasn't sure what exactly is the issue.

Could the solution be in flashing the phone?
I already got it converted to ROKR in the same service shop.