Ken, I might suggest your pen table file is not complient for some reason if it is in the working directory.
I have a very simple pen table called table.pnt in my working folder and it works wonders.
Copy all the lines below into a file called table.pnt, all lower case, and select "use pentable" in the export PDF dialog. This is merely a test where the output should be all thin lines. Also make sure there is not a hidden .txt extention on your filename.
! All pens are set to .002 in this file. This is a basic setting.
! To vary thickness, tweak individual values for different pens.
!
! Other options are available. Refer to documentation on "pen table files"
!
!
!
pen 1 thickness .002 in
pen 2 thickness .002 in
pen 3 thickness .002 in
pen 4 thickness .002 in
pen 5 thickness .002 in
pen 6 thickness .002 in
pen 7 thickness .002 in
pen 8 thickness .002 in