External Hard Disk no Longer Visible - Terminal Help

Hi guys, i have a WD 320 gig hard drive that for some reason has stopped appearing on my desktop, i have already checked it visible on the view options but it appears nowhere, System profiler lists it, and it can be seen in Disk Utility, yet i have no access, it seems it wont mount..

Now, in Disk Utility the hard drive is listed .. 320.0 Gig WD MY Book ES Media,
it is mounted, can be verified, and repaired and is fine.

Below that is the part im after, named "Travieso" its the volume i want to open, same drive, it is not mounted and will not mount, however disk persmission, verify and repair are all fine, the buttons are available and all successful.

Ive read there are some terminal commands i can use to make it accessible to me again yet i can not understand them entirely.

Under system profiler the disk is listed as -

My Book ES:

Capacity: 320.07 GB (320,072,933,376 bytes)
Removable Media: Yes
Detachable Drive: Yes
BSD Name: disk2
Product ID: 0x0906
Vendor ID: 0x1058 (Western Digital Technologies, Inc.)
Version: 0.12
Serial Number: 57442D574341505A30363235343635
Speed: Up to 480 Mb/sec
Manufacturer: Western Digital
Location ID: 0xfd100000
Current Available (mA): 500
Current Required (mA): 0
Partition Map Type: APM (Apple Partition Map)
S.M.A.R.T. status: Not Supported
Volumes:
Travieso:
Capacity: 319.94 GB (319,938,674,688 bytes)
Writable: Yes
File System: Journaled HFS+
BSD Name: disk2s3

Can someone please help with this issue?

 

oh ive tried this but it wont allow me to mount the volume! it will however allow me to repair and verify it (both which check out ok), this is whats causing my confusion

 

i have, im using data rescue and it can load and rescue everything just fine.. however i really wish it would show up, everything is fine except it doesnt show!