Michael, I'm not picking on you here so don't take offense. I think you're not understanding the value of reading a vector based EPS (Encapsulated Postscript) file appropriately. The best way to use a vector file is to be able to open it with little or no further processing needed.
EPS comes in lots of variations. The most confusing of which is the bitmap versions generated out of various bitmap image editing applications such as Photoshop and Jasc Paint Shop Pro. Their only relation to Postscript is in the area of color management. A Photoshop EPS will not run your plotter. An Illustrator EPS usually will.
If you are using Jasc PSP as part of your regular procedures, then you are regularly converting perfectly good vectors into bitmaps and, I presume, autotracing them back into vectors so you can use them for plotting.
The net effect is two generations of serious image quality deterioration. Once when you open the vector file in PSP and another when you autotrace it back into vectors.
Sometime when you have five or ten minutes to spare, take a known to be good vector file that has been professionally prepared and put it through your PSP procedures. Then bring it into Flexi and group it. Next click on Import and bring in the original file, group it and make it a different color. Now select both and enter Control +5 to justify them on both axes. Finally compare the original to the processed one and note the changes that have occurred.
If you want to be able to open all EPS files, the best solution is to spring for a copy of Adobe Illustrator and keep it upgraded. The difference in the quality of what you cut on your plotter will be noticed by enough customers that your investment will be recouped on a frequent and regular basis.