Calling SSIS Package From C# Code

I am using the following code to run my SSIS package:

Package package = app.LoadFromSqlServer
("\EPSROI\dts_Client_Eligibility_Import", "SQL32", "username",
"password", null);

Variables vars = package.Variables;
vars["InputFile"].Value = txtInput.Text;
vars["OutputFile"].Value = txtOutput.Text;
vars["Client"].Value = cboClientName.SelectedValue.ToString();
vars["Chopper"].Value = Chopper;

DTSExecResult result = package.Execute();

It runs fine on my machine; however, on anyone elses machine "result" comes back as "failure". We have figured out that it is loading the package and variables fine but failing before the first step of the package. Does anyone know why this would be? Or how to fix it? I am totally stumped considering it works fine on my machine.

Thanks.
Danielle