My external SSD stops running

Hello all,

So I have an external SSD (Samsung Pro 840) that I've been using as my Itunes and Iphoto Library since I bought a new Macbook Pro Retina 15inch (2015)

It is in a anker enclosure (http://www.ianker.com/product/68AN25EN-BPA).

It's been working fine until Itunes 12 appeared. Since then, everyday my SSD stops working.

Sometimes it doesn't let me open itunes or I can't access the drive, and even Disk Utility freeze to death

Or, if Itunes is already open, but I don't use it for a while and I hit play again, it will freeze forever.

I need to disconnect and reconnect the SSD, and sometimes the only way to restore everything is to restart my computer.

Any clue on what could be happening?

Thank you

dB