i shoulda listened to that. i had BBM 5.0.0.3 installed and wanted to try to upgrade to BBM 5.0.0.7. my phone only has email and no data, so i cant download from blackberry's website directly on to my phone. i tried searching for a way to download it to my desktop and then use desktop manager to load it on my phone
i found it from some article, and when using desktop manager, i unselected the older version so it would delete, and selected the newer version so it would load.
after doing it, there was an error message and i can't find the icon for the newer BBM in my menu. if i go to options > advanced options > applications, its listed there, but its no where to be found in my menu. spent an hour with tech support from my carrier, wiped my phone endless times, reset the network on my phone, etc, but i can't get it back. even when its back to the factory reset state, theres no messenger, not even the older one.
Try this, in your blackberry application menu with the icons, hit the blackberry logo button, and click on show all. Is that clicked? Maybe for some reason it is hidden.