It sure sounds like your drive is formatted as FAT32.
Regarding the RAID setting, if you did not set up a RAID set, the 'settings' under the RAID button are irrelevant. And anyway, you wouldn't have a RAID set with a FAT32 drive, much less a single FAT32 drive.
I think you have two problems - 1) the drive is not formatted properly - needs to be Mac OS Extended and 2) your cam & external FW drive attached at the same time - I think you have a Firewire conflict between them.
But you have to fix the formatting first. Be sure to back up anything you need to keep because formatting will completely erase the drive.
Finally, not to alarm you, but regarding your internal drive, with only 4GB left you are dangerously close to crashing your system if that drive fills all the way up. You need to get stuff off that drive. You should really keep at least 15% - 20% of your system drive empty at all times. OSX needs that room to operate.