Disk insertion error

[gintonic]

I know there have been (too) many posts with a similar subject lately, nevertheless those hints couldn't solve my problem....
I have a Intel macmini coreduo 10.4.8 and an external laCie harddrive. Last week my computer crashed and I had to turn the power off. On restarting the external drive didn't mount anymore saying "The disk you inserted was not readable by this computer". /Volumes shows only my HD.
What I did:
- Unplug the drive, starting up the macmini, everything works fine, plug the hard drive =>same error
- In Disk Utility the harddrive shows up, but the volume Name doesn't show up (grey). The Verify and Repair Disk permissions are greyed out, repair disks is possible but doesn't show any errors.

Fortunately I have an iBook where I plugged the laCie yesterday, there everything is fine, all files are there... Of course I could copy the laCie content with my iBook to another HD, format the laCie on my macmini and copy the data back, but isn't there another solution? Since all the data are there I suppose I'm only some clicks away from Re-mounting the laCie on my macMini.

thx