PGP got the best of me...

i take credit card orders over the net thru the interchange shopping cart. that cart software requires pgp be installed at the cpanel server and on my computer. did that. works. can decrypt orders fine on my home computer.
but i tried to install the same pgp at my office computer. didn't work. message said something like "can't decrypt because the private key does not match."
that's where i'm confused. i did a clean install of the pgp software from a fresh download at my office. then i imported the keys from a floppy disk i created on my home computer. i even copied the keys in the same directory on my office computer. no go.
anybody know what gives?
2 the proprietor of this forum: nice place u got here.