Yes, thanks for that.
I turned off all community and local modules to see which one may be causing it.
It made no difference to the error I was experiencing af ter I did this and flushed the indexes and caches.
I did some further research in to the log file errors and found it was the shopping cart, but it was hidden in a 3rd party module for configurable items located in the renderer.php
I was able to patch this from recommendations on the Magento forum and now is all working.