aha - I have found a way around this by changing the cross tab query:
TRANSFORM Nz(Count(qry_cardiology1.EpisodeID),0) AS CountOfEpisodeID
SELECT qry_cardiology1.ReferringHospital
FROM qry_cardiology1
WHERE (((qry_cardiology1.ReferringHospital)="Dudley" Or (qry_cardiology1.ReferringHospital)="Walsall" Or (qry_cardiology1.ReferringHospital)="Wolverhampton") AND ((qry_cardiology1.RequestDatetime) Between #1/1/2011# And #1/31/2011#))
GROUP BY qry_cardiology1.ReferringHospital
PIVOT qry_cardiology1.NumberOfWorkDays2 In (0,1,2,3,4,5,6,7,8,9,10,11,12);
I do not have referring hospital as row heading though which is mildly irritating