Help with appearances

in the following script I assign an appearance to be used when I sign a PDF document:

// Login -- *****change as appropriate*******

ppklite.login("????", "/g/Standards/Engineer Seals/Digital_ID/From Hard Drive/Thomas_Evans_2014-02-07_AAPv9.pfx")

f.signatureSign(ppklite,{password: "???", appearance: "Tom Evans MO 2014-02-07 Seal"});

ppklite.logout();

When I run the script the appearance shows up as standard text and not the image assigned with this appearance.  Why is that happening.  I am using acrobat pro xi.

Any help would be greatly appreciated.  FYI this script run in acrobat pro 9 and x.

Chip