ozzy47, kh99 & Lynne thank you very much for your help with this issue.
I'm not sure why but for the last 4/5 days everything seems to be running smoothly. Maybe the database took a day or two to recognise the that the tables were changed to utf8_general_ci. So feeds are good.
The characters in the usernames were ok after I edited them from the box to the correct character.
Thanks again