I have a 640GB external HD that has one partition formatted as HFS+. It's attached to a machine running OSX 10.6.6. Now I want to split some of the HD's free space into a new FAT32 partition, without having to reformat the whole HD and losing all my data. I read that I'm supposed to be able to add new partitions in the Hard Disc Utility by clicking the "+" sign, without any loss of data. But in my case the "+" is not clickable and utility says that the partition cannot be altered.
Can I do this without reformatting the whole disc? If so, how?