If you have a file that imports correctly for one user and not another, it could be the result of those users having different permissions or user configurations within Raisers Edge. For example, an RE user that has access to the SSN field can successfully import a file that contains SSN, but another user who does not have access to the SSN field will be unable to import the same file. An RE user that is configured to use the Campaign description can import a file containing the description but another user who is configured to use the campaign id will be unable to import the same file.
To resolve these kinds of issues, ensure all IOM users are configured the same within RE. Or, create a new RE login that everyone uses when configuring IOM and running imports.