Can't mount external HDD all of a sudden?!

Hi, this is something that I've tried to fix and can't get it to work. I have a MacBook Pro and to it is attached an external 2.5" laptop HDD in an enclosure that draws power from the USB 2.0 ports. I have used it like that for about a month with no problems. It worked fine when it was plugged in and I was able to transfer data and everything. Today I plugged it in and it worked fine. I ejected it and forgot that I needed something else from it and when I plugged it in again I got an error saying that, "The disk you inserted was not readable by this computer."

I tried doing the whole disk utility thing and that didn't work. The OS sees the HDD as a HDD and nothing else. I have tried using Drive genius and Tech Tool with no luck. There are no bad sectors and the drive still sounds fine. To make a long story short is there any way I can get this back to working order? I don't want to loose all the stuff that I backed up on it. Any help would be greatly appreciated. Thanks in advance!

By the way when I do the repair I get this:

Checking HFS Plus volume.
Invalid node structure
Invalid B-tree node size
Volume check failed

Error: The underlying task reported failure on exit

1 volume could not be repaired because of an error

i'm just going to state the obvious...

have you restarted your mac?

have you tried the disk on another system?

Thanks for your reply! Actually I did for get to mention that. I restarted 3x and also tried it on another system as well as a Win XP machine, to no avail. Any magic advice would be great!

when u rebooted, and u plugged it in, did it ask you if you wanted to initialize this ext disk?

this happend to me, and it asked me that, of course i INTed it

It comes up with a red stop sign icon with an exclamation mark and then says, "The disk you inserted was not readable by this computer" The options it gives are Initialize, Ignore, and Eject.

You did eject the drive before pulling out the USB cable? Just making sure as I know many who just unplug the cable without unmounting the drive by dragging it to the trash first and a lot of times the drive gets corrupted.

Just being sure.

Yes, I ejected the drive and made sure that the icon disappeared, as I've done before... I'm still racking my noggin... Thanks for the replies.

did u click on initialize?

if it pops up, u need to

I clicked on initialize and tried to use the repair feature and that is when I got the error messages. Also in the window on the left there are 2 different icons of the drive that I am trying to get working, the top one has the drive capacity and serial number and then underneath it offset a little to the right is another icon that says "disk 1s2". Does that have anything to do with this problem?

So all is lost I guess? Should I just format it and say good-bye to all the stuff that was on there?

Am I the only one that this has happened to? There has to be a way to fix this... =)

i guess as a last resort you could do one of the following...

unmount the drive itself from it's enclosure and mount it in another cheapie firewire or usb enclosure.

or

do the same but mount the drive directly into a spare bay on a tower pc or mac.

if it doesn't work after both of these, then i'd assume you've got a fried drive.

Try booting from your OSX install CD and see what disk utility says about it there.

I'll try both those options and see what happens. Thanks very much.

Beyond what has been recommended as of late. I would say you have a failing drive. And it will need to be replaced. Has it been dropped, or suddenly jostled at all

Have you tried pluging it into a PC?

Well I tried all of the suggestions but none worked. I ended up just biting the big one and formatted it. It is working fine now... to answer your question ICM, it has always been on a desk and never abused. Don't know what caused it. Thanks everyone for your help. Happy Holidays!