I got an issue with MMC & Mini SD card. My desktop (running on Windows 7 Ultimate 32bit) couldn't detect both memory cards when I plugged these cards to a USB card reader. Sometimes the cards were shown as Removable Disk (despite the fact I renamed them as HJN86) but couldn't be accessed when I double-click on it.

The light indicator on the card reader was lit green, showing that it is operating normally. Whenever the desktop did not detect the memory cards, the cards' contents became corrupted when I reinserted it back into my mobile phone because I had to plugged out the reader without ejecting it (it did not show up in the device list of Safely Remove Hardware and Eject Media icon in the system tray).

Any ideas on how to resolve this issue?