I fixed the amount option by creating a roll up summary field (which pulls two decimal points over, instead of one). 

But now, I'm running into a bigger problem with our end users:

I have setup a workflow that triggers an email alert (described above).  The workflow kicks off when a stage of an opportunity is set to "Closed Won" and a picklist to send alert equals "Yes".

As an administrator, I can select both options and save the opportunity record (and workflow, email triggers).

BUT when an end users tries to do the same, he's prompted with an error:

" Error: Invalid Data.
Review all error messages below to correct your data.
You do not have sufficient privileges to access the controller: SortedLineItemsController"

Do you know why this is happening?  

Here is my controller:

public class SortedLineItemsController {
    public Opportunity opportunity { get; set; }
    
    public OpportunityLineItem[] getSorted() {
        if (opportunity == null || opportunity.opportunityLineItems== null) {
            return null;
        }
        
        // TODO: Add your sorting logic here (demo just reverses the list)
        OpportunityLineItem[] result = new OpportunityLineItem[1];
        for (OpportunityLineItem item : opportunity.opportunityLineItems) {
            result.add(0, item);
        }
        
        return result;
   }
}

 Any help is appreciated.  I'm under a deadline and can't seem to figure it out.  Is it in the code or something I have to change under the salesforce setup?