after writing a typescript i get never the results in my document as expected. Please have a look in the attachment.

When i do \showbodyfont[12pt] there is my rm typeface (MinionPro) in the row \tt visible (column \tfx), in \showbodyfont[13pt] this is not the case. Strangely enough, the rm typeface is apart from that never visible in my document but should be. Instead there is the ss typeface. I´ve no clue whats going on here. Please help.