Hi Omke,
Thanks for the response. I hope we can get this working.
Bridge CS6 was installed when I installed Photoshop CS6. It is in the Applications folder at the root of my main hdd.
When I go to ~Library/Caches/ there is a folder for com.adobe.bridge5 but there isn't one for com.adobe.bridge6
What should I do next?
Thanks.
When I go to ~Library/Caches/ there is a folder for com.adobe.bridge5 but there isn't one for com.adobe.bridge6
Your in the wrong folder. Follow the path you have discovered yourself using the pref settings Curt suggested 
~library/caches/Adobe/Bridge CS6 and inhere should be 2 files:
Adobe Bridge Plug-in Cache
and the folder called Cache. Inhere should be 4 folders called '254', '1024', 'data' and 'full'
All those folders carry the content of the respective quality of the thumbs and preview as well as 100 % cache and Bridge database.
Any way, Since you have not used Bridge you have no relevant amount of cache and I would suggest you quit both PS and Bridge and manual delete both the items (plug in and folder called cache at the end of the Bridge CS6 path mentioned above.
(both files will refresh itself after a restart of Bridge).
To be on the save side also visit in same user library the folder Preferences and look for the file called "com.adobe.bridge5.plist" (yes it is Bridge 5 that comes with CS6, all Adobe apps have their own version number and they are presented in the same Suite version. CS6 has PS version 13 and Bridge version 5
)
also drag this file to the trash.
Then hold down option key (alt) while starting Bridge and this should give you the option to reset the preferences as mentioned earlier in this thread.
Choose reset prefs and try again.