iPlot pen table ignored by MicroStation?

Greetings,

I have a client-delivered iPlot pen table (*.pen) that I"m trying to use to plot DGN files to PDF. However, my preview and resulting PDFs are acting like no pen table is attached - "what you see if what you get" (WYSIWYG) is what I get when in fact I know all elements should be black. If I detach the iPlot pen table, nothing changes in my plot - it's like it was never even attached.  The proper PLTCFG and PEN files are loaded when I go to print/plot.

Is there any setting that could be causing this behavior?

I know the ability for MicroStation to use iPlot PEN files when plotting came in SS3; I am on SS4 08.11.09.829. In case it affects anything, I am in a ProjectWise environment (08.11.11.574 server, 10.00.01.67 client). 

Thanks for any info!