SSIS Package fails when execute from SQL Agent (job)

Hi,

I have a problem where I have an SSIS package (SQL Server 2005) that won't run properly from SQL Server Agent, but it runs fine when kicked off manually from Integration Services -> Run Package or when run in debug from Visual Studio.

The package is very simple take data from a table and load it to flat file. I created a login, credentials, proxy (used the credentials) and the proxy user has access to the shared path, i gave UNC (\\servername\test\test.txt) but still the job is failing with error "Executed as user: proxy account. The package execution failed. The step failed". i am able to execute by using UNC path using ssis directly. I have given the package file location in the job step. The account that am using to run the package from job has all permissions.

Thanks,

Eshwar