External Hard Drive no longer mounts

Hi there,
I have a system with this spec

MAC OSX 10.6.6
Model Name: iMac
Model Identifier: iMac8,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.4 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 6 MB
Memory: 4 GB

I've been running this fine with an iomega1 external 1tb hard drive for two years now. However its suddenly stopped mounting. It turns on and spins fine and I can access it in the Disk Utilities however it won't mount. I have tried to "verify" and "repair"first aid option and it keeps saying the hard drive appears to be fine and won't mount.

Please help! if I have to get a new hard drive thats fine however I really need to get the old data etc off this hard drive as I have a lot of uni coursework on there. When I go into system profiler, this is the result of the usb:

External HD:

Capacity: 1 TB (1,000,204,886,016 bytes)
Removable Media: Yes
Detachable Drive: Yes
BSD Name: disk1
Product ID: 0x0370
Vendor ID: 0x059b (Iomega Corporation)
Version: 0.00
Serial Number: 91B42FFFFFFF
Speed: Up to 480 Mb/sec
Manufacturer: Iomega
Location ID: 0xfd100000
Current Available (mA): 500
Current Required (mA): 2
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. status: Not Supported
Volumes:
Capacity: 209.7 MB (209,715,200 bytes)
Writable: Yes
BSD Name: disk1s1
Time Machine Backups:
Capacity: 999.86 GB (999,860,912,128 bytes)
Writable: Yes
File System: Case-Sensitive Journaled HFS+
BSD Name: disk1s2

Just a thought, Do you have "Parallel Desktops" running Windows XP. For some reason disks will not always mount on the mac OS X side. I had this happen to me and had to shut down Parallel's to mount disks.

Hi Pauzol,
No I don't have parallels running its just OSX running.