External Drive is recognized but won't mount to the Desktop/Finder

I've searched the support forum and I can't seem to find this problem... MacBook Pro 2.5Ghz Intel Core2Duo. External LaCie 500GB drive. I bought TechTool Pro 5 last week to clean this external drive out and repartition. I did a 7 pass erase, surface scan, and repartitioned the drive for 3 partitions. Everything went smoothly and no errors occurred. So, I attempted to change the Icon for one of the partitions. Ever since then, the volume will not mount to the desktop, therefore is not available in Finder. Using Disk Utility, the volume is there and will verify and checks out without needing repair. Using Tech Tool to rebuild the volume checks out as well. I'm stumped!! Any ideas? I'm sure it's some silly thing I've just never heard of, but I don't have any ideas left in me.

other checkpoints.... In Disk Utility: the drive is in the sidebar, but there is no "Mount" option available for the drive, since it is, apparently, already mounted.

Also... If I use the Finder menu item Go -> Go to Folder and enter "/Volumes" (without the quotes), I can see all 3 volumes on the external drive.

There is about 28GB of data on this volume, but I do have it backed up.

Thanks for any info.

See if this article helps. It refers to internal drives but the same applies to externals as well. Let us know.

Regards.

OUTSTANDING! That was the problem and that was the solution. Thanks so much. I was sitting around in Apple support for 3 days getting nowhere, and you handled it in one response and under 24 hours. Thanks again.

Glad we could be of help. Come back and see us....

Regards.