Hi Dustbak, I use a 20GB Magazine and my computer it is a Mac. When you open Disk Utility has many options to format the Magazine which one it is the correct? and how do you proceed to create multiple ones?
You need to erase the existing partition(s) first. After that you have a completely clean disk and the option 'partioning' should be available to you. With this you can partion the disk, meaning to chop it up into one ore more parts.
The partioning option allows you to select both the size as well as the desired filesystem.
You should select the desired size of the partition and FAT32 as your filesystem. I believe the Mac Disk Utility also immediately formats the partion after that but if it doesn't you need to format it afterwards.
After these steps it should be functioning again.
Good luck, if you have any other questions don't hesitate to ask or send me a PM.