ODBC Password Not Saved In Configuration File

Hi,
 
I have an SSIS package that pipes data from an iSeries data source to a SQL Server table. The connection manager I am using is the .Net ProvidersOdbc Data Provider
 
When I run this SSIS package on my developer PC (from inside BIDS or using the Management Studio Execute Package Utility) it works. However when I run the package from within a SQL Server Agent Job it fails.
 
I have enabled logging and the error message given is:
System.Data.Odbc.OdbcException: ERROR [28000] [IBM][iSeries Access ODBC Driver]Communication link failure. comm rc=8002 - CWBSY0002 - Password for user MALLPRESS on server SMICHC is not correct, Password length = 0, Prompt Mode = Never, System IP Address = 172.16.0.4  ERROR [28000] [IBM][iSeries Access ODBC Driver]Communication link failure. comm rc=8002 - CWBSY0002 - Password for user MALLPRESS on server SMICHC is not correct, Password length = 0, Prompt Mode = Never, System IP Address = 172.16.0.4
It gives the message €œPassword length = 0€? despite the fact that I have specified a password in the package.
 
To try to get around this I have added an XML configuration file to the SSIS package. In this configuration file I€™ve set values for the ConnectionString, UserName, and Password.
I still get the above error about a password length of 0.
 
I have also tried to execute the package using dtexec, but this gives a similar error.
The SQL used to run this is:
xp_cmdshell 'dtexec /sq "SCSRV-06DTS PackagesStagingStagingBranchImport"'
 
This has got me stumped, and I€™m not sure where to go from here as these packages need to be programmatically run each morning. At the moment I am manually running them from within BIDS.
All packages that don€™t use an iSeries connection manager run successfully in SQL Agent jobs.
I have also tried using the OLEDB connection manager (ibm db2 udb for iseries ibmda400 ole db provider) without success.
 
Any help would be very appreciated.
 
Thanks, Matt