Maybe the original file got corrupted when I transferred it to the TiVo.
I recaptured the codes with OmniRemote and converted it with Sam Highleys's converter and transferred it to the TiVo. Then I used the following syntax:

[TiVo [p0] ~]# tivosh
% source stb.tcl
% loadcodes
% exit

followed by a dbset with my source and box number and it works now.
Thanks again for your help.