I have finally resolved my issue after over a year.
For anybody else, here is how I did it.
Firstly I opened the Intel RST Management console and disabled acceleration from the SSD drive that acted as a Cache for the primary drive. Once I did this the freezing stopped completely, turning it back on meant that the issue came back.
Upon identifying that Intel SSD caching was the problem, I did some more googling and found that it may be due to the Link Power Management functionality within Windows 7 causing a conflict.
I followed the registry setitng changes from this site and for the last 4 weeks have not had a reccurance of the issue.
Hope this helps anyone else who may also be having this issue:
http://windowsforum.com/threads/intermittent-ssd-freezing-on-newer-laptops.69796/