It doesn't take much to figure out what "d-max" means. It should be easy to infer "density - maximum" thus "maximum black."
OTOH, I'll take your word for the paper.
It is of course possible that the blacks aren't black enough because the print is simply flat and needs more contrast to push the shadows blacker and the highlights whiter. Could be the negatives are too flat and could be the print just needs to be made with a higher contrast VC filter.
Jenni, this is a variable contrast paper. You do have variable contrast filters, don't you? What filter did you use to print the prints you are unhappy with? Could you scan one and post the image? Also, and excuse me if you mentioned this, but what print developer are you using? And how long are you developing your prints? In my experience most fiber based papers benefit from a longer-than-usually-recommended development time. I develop my RC prints for two minutes and FB for at least three.