Procedure fails when called from a job

Hi Folks,I have encountered an interesting phenomenon whereby a stored procedure works flawlessly when called manually but when called from a Job Returns a fatal error:[b]The conversion of the data types varchar to datetime produced a value datetime out of interval[/b](I had to translate that from German so I hope it's accurate...)Can anyone explain why that might be? It is a SQL Server 2008R2 fully-patched machine.....Thanks!Regards,Kev