The Payer Name in Analytics Reports does not match the name of the Account record.
The Payer Name in the Analytics Reports is based on Account Name for the payer Account where Account.Payer_Id_vod = the Payer_Id_vod field in the data file for some reports. It also can be populated from the Payer_Plan_vod__c field in the data file.
Since the reports generate the Payer Name from two different sources, always keep the Account Name and the Payer_Plan_vod__c field in the Payer Data File in sync.
CRM Help Documentation: Default Functionality for Fixed Reports