Hey Rob,
What size are the labels that you are using? Because what might be happening is that if say your label is 1x3 (inches) and you have white space around your bitmap, it may just be printing the white space. Theoretically though, it should just see the Eltron as another printer and print from paint. You can set up the page size/label size, margins and all that from the printer properties(which you already probably know). I'm not familiar with EPL2 language. The printer that I was using was an Eltron 2622/2722. I didn't have to use the PCL for the printer. One thing that you need to watch though is that some of the text MUST BE ASCII
Ex: crsReport1.FormulaFields.Item(1).Text = Chr$(39) & "PO#: " & strPONumber & Chr$(39)
This is just an example of a section of code that I put in. It calls a PONumber and turns it into a barcode, but I needed to use ASCII text in order for it to work (39 = ,).
Another thing that you have to watch is the drivers for the printer and the versions and such with ELP2.
All I can suggest is to try setting margins or somehow setting a border around the image from VB.net. That way you'll be able to see if the image is getting bigger or smaller on the label.
CrystalReportViewer.CRViewer1.Height = 400
CrystalReportViewer.CRViewer1.Width = 600
This code works to size the crystal reports window, so try something like this to size the image to the size of the labels.
Else, if you have a version of photoshop, try printing the label from there. Photoshop has many great features, and you may be able to find what your looking for there. I'll keep thinking about this though, and if I get any other brainwaves I'll let you know.
Keep me posted!
Brad