Same behavior on 10.04 LTS upgraded from the prior LTS: blank page ejected from printer and same errors reported ("/usr/lib/cups/filter/pstopdf failed" and "Error: /invalidfont in /findfont").
Removed ttf-mscorefonts-installer and was able to print again.
Same behavior on 10.04 LTS upgraded from the prior LTS: blank page ejected from printer and same errors reported ("/usr/ lib/cups/ filter/ pstopdf failed" and "Error: /invalidfont in /findfont").
Removed ttf-mscorefonts -installer and was able to print again.