Seems that there was a leftover file from Open SEF that I had to delete using FTP. I had originally used the Joomla admin to remove Open SEF component, however, this did not entirely delete all of the files.
I can not remember exactly where I found it. Just make sure that all of the Open SEF files are completely removed.
One word of caution. Ever since the change over to SEF URL's, my clients directory listings have disappeared from relevant G search results. Not just one or 2 but basically all of them that were affected by SEF have disappeared for results. I imagine g is just recalculating my Pr, however it seems to be taking quite a long time.
Regards,John