I found a fix to that problem.

My Blackberry Storm when using Pocketmac on an itel 10.5.x machine would not sync and gave me the error "no mounted media card found". Also the storm would not show up as a USB volume on any of my Mac's desktops.

I found the solution here:

http://forums.crackberry.com/f79/usb-mass-storage-mode-will-not-enable-250500/



The fix was to hook up my Blackberry to a PC, search the internet for a file named something similar to:

BB storage Activation

And once I ran the program, it updated my blackberry and my blackberry would show up on my Mac's desktop and sync.