VS 2008 - Print Doesn't Work

I have been handed a program written by someone else, that has been deployed and doesn't work correctly after deployment.

Basically we have a button with the following:

Code:
protected void btnPrint_Click(object sender, EventArgs e)
{
using (PrintDocument pd = new PrintDocument())
{
pd.PrintPage += new PrintPageEventHandler(printPage);
pd.Print();
}
}

in Dev the print button works everytime. I noticed that this references System.Drawing and that wasn't being deployed as part of the solution. I changed this so that this dll gets deployed as part of the solution into the bin folder for the app, however it has made no difference.