Have you tested the Wd My Passport with our software for errors? It's called WD Data LifeGuard Diagnostics and can be downloaded freely from our official web site here: http://products.wdc.com/support/kb.ashx?id=Cl0HeB
My advice is to run the extended test. Come back afterwards to share what happened.
Besides the programs mentioned by you, you could also try to access the data on your drive using Linux Live USB / CD. Within the Ubuntu forum you can see the steps how to make a bootable flash. Once you have downloaded the .iso file, change the boot priority on the computer where the USB is placed. It is done through the BIOS and you must change the boot priority to be from USB ports and not the HDD. When it boots from the PC, you have to click on try option and not on the option to install the OS.
Hope this helps. Keep me posted and good luck!