This is not a GB question it is a newly installed Logic Pro 8.
A lot of the presets that Logic uses actually come from the Garageband presets and folders.
I too had this problem, and I also have never touched any of my garageband folders. This topic was huge when LP8 first was released, so if you do a little digging around you'll find some threads on the topic. I think the problem was with people who had the latest version of GB installed. For some reason the Logic installer deleted some of the presets that were already on your system because they were included with GB 4.
If memory serves, the fix was to leave Logic alone and reinstall Garageband from your computer restore disks. You'll have to use a program like Pacifist to extract the GB installer from the restore disks and then run the installer. That will reinstall GB and all of its content, thereby installing the instruments you're missing.
If I were you, I'd first do a search for other threads. I don't totally remember if this was the only thing you had to do to retrieve that content, but you should be able to find definitive answers in other threads. Good Luck!
