Is the problem only seeing from your Laptop/Desktop computer? Or are you not seeing the MicroSD card on the Blackberry.
Mine is working fine.
My Blackberry is password protected.
Under Options >> Media Card, my settings are as follows.
Media Card Support = On
Encryption Mode: = None
Mass Storage Mode Support = On
Auto Enable Mass Storage Mode When Connected: Yes
When I connect to my Computer,
Handheld Manager or Desktop Manager prompt for my Password.
My Blackberry brings up a message, "Mass Storage Mode is being activated. Enter your device password to grant access"
After entering this last password, my Micro SD card is available as a removable drive.
If I use the Media Manager in Desktop Manager 4.2 Sp2, then I will enter my Security password again, and then I am good to go.
Hope this info is helpful.