(Newbie alert) Zip drive confusion.

Hi all, I have just tried to access my USB 250 Zip drive in SUSE 7.3 Pro, only to receive the following message: "Could not mount device. The reported error was mount /dev/sda4: unknown device." I have checked and ziptool is installed, I have a Zip icon on my desktop, but obviously, something needs to be configured somewhere. I read /usr/share/doc/packages/ziptool/README, but there wasn't any help as far as I could decipher. Any ideas? Cheers, Brian