Osx 10.4.2 Eudora 6.2.3 & Entrust 6.2.1


I recently had a user upgrade their Eudora client from 6.2.1 to 6.2.3 with Entrust 6.2.1.running fine under 6.2.1 Upon completion of the upgrade the Entrust encrypted document defaulted to apple certificates and key chains. I deleted the key chain files for mail but problem still persists when trying to access the file. In the past I have had the sender resend the document and this resolves the issues. Any ideas how to correct this with out resending the file?
Thank you