I installed the free version of SIG on my Joomla site and it was fine  so I paid for and installed SIGPro. Since then I have never been able to see the thumbnails - only blank white squares with a black bar at the bottom which says "Click to open image"

I've read all the documentation and searched on the forums and so far nothing suggested has worked.
I have made sure that
  the cache in Joomla is enabled and writable
  there are no capital letters / special characters etc in the filenames of the photos for the gallery although I know that shouldn't matter in the latest version
  I am running the latest version of SIGPro - currently using version 2.0.5
  the GD image library is running - I am using localhost on a Mac to build the site in MAMP

I am using PHP version 5.2.5 and Joomla version 1.5.20

Any advice would be very welcome as I really need to get this plugin to work!
Thanks

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