Commenting the Section Access part, reload the document and select that user, select "Speciality Reinsurance", then go to File, Reduce Data, and select "Keep Possible Values". My guess is there will be no records left, so when your user accesses the document, the reduction takes place, and he's only able to see the records that is linked to. That reduction is what Section Access does.
If this is not the case, split your security into two tables, one with NTNAME, USERID, PASSWORD, ACCESS and, say, GROUP and create another table in Section Application with the possilbe combinations for GROUP, SOURCE and DEPARTMENT.
Maybe the blank between Speciality and Reinsurance is causing some issue?
Hope this helps
Thanks for your response Miguel... I figured out what was going on... I'm not sure it'll be particularly helpful to anyone else but just in case:
Way back down the line we introduced a department_name_tidier_Spreadsheet.xls which renamed a load of dodgy/redundant department names to 'Other' also changed everything to uppercase in preparation for Section Access.
Since then we'd tidied up the DB to remove the redundant names. I forgot about the xls and therefore as there was no record in the xls for two 'new' departments these weren't then passed through to section access hence their exclusion.
So, I added the departments to the xls and section access now works! Phew... Mike