Volume Rebuild taking a very long time

Hello,

I have an external USB 2.0 500 GB hard drive that has some minor problems with the directory (reported by Disk Utility). The drive has approximately 170 GB available. My computer is a Macintosh Quicksilver G4 (867 MHz).

I started Volume Rebuild about 4 days ago, and it's still at the step "Rebuilding Directory Structures" - is it possible that it should be taking so long to rebuild the directory structures? There were no errors reported during the first two steps.

Thanks in advance for any advice / help.