I have tried everything I can think of and everything I have read on multiple forum sites (including blackberry.com and roxio.com) to try to get the Media Manager to recognize my Blackberry 8310 to no avail. I have downloaded and reinstalled and wiped and reinstalled all flavors of the desktop manager (the version that came with my blackberry 4.2, the version suggested in these forums elsewhere 4.2 SP2, and even 4.3) and it still won't recognized my blackberry from the media manager (roxio... who chose that piece of poo software application should be fired by RIM).
I tried it on two different PCs running windows xp home (all the latest patches and sercurity fixes) and the same problem persists. I don't have a microSD memory card, but the blackberry is new and has no other thirdparty software apps or images or emails stored on the device... fresh out of the box the memory manager does not recognize the device.
I can sync it with my email and calender and my address book and the rest of the desktop manager syncs work just great... it is just that darn Media Manager... any advice (other than deleting my previous install including program files and folders and reinstalling i mean).
Does it give you an error? Or does it just not open?
If the Media Manager opens, your computer is at the top half of the screen and the bottom half is the blackberry. I believe you need to have the third or fouth tab on the left side clicked, that is the device. At least that is how mine looks.
Without a micro sd memory card, the device's storage space is very limited. I had this same 'problem' you describe until I bought the extra memory card. This is also how you get the option to enable mass storage.