I have finally sorted out this issue.
Not sure in the end what actually caused it all?
I ended up re-installing MapPress then manually (via the database) deactivated all plugins. I then went in and deleted MapPress again and then activated each plugin individually.
All seems well now but I have had to leave off using MapPress. Not sure if the error message to do with ‘missing data tables’ was a WP Ver 3.6 update thing which I did on Sunday or a conflict with MapPress or some other plugin but was getting way too costly in time.
I use MapPress on other sites including the Pro version but haven’t updated them to WP Ver 3.6 yet.
If you need to ask any questions please let me know.