By default, the SQL Agent SSIS step type executes the 64 bit DTEXEC binary.

There may be other workarounds for this but the one that I am using the moment is to change the step to be a "CmdExec" type and explicitly execute the 32 version of DTEXEC from the x86 folder. You can get the command line for the DTEXEC from the existing job definition . The command line would look something like the following

"C:\Program Files (x86)\Microsoft SQL Server\100\DTS\Binn\DTEXEC.Exe" /SQL "Maintenance Plans\Daily Database Backup" /SERVER "YourServerName" /CHECKPOINTING OFF /SET "\Package\Subplan_2.Disable";false /REPORTING E

This example is for one of my SQL2008 servers. You may need to adjust the command line depending on what you have installed and where it is installed to.

Note: the quote marks are important - both for the name of the dtexec binary and in the