We are able to reproduce this problem, but only when the Duo 280c is running System Software version 7.1.1, and the AppleShare Server is at version 3.0.
If the Duo is running System Software 7.5, or the AppleShare Server is version 4.0 (or 4.0.1) there is no problem with remote launching of Persuasion by the Duo 280c. We tested that the Duo could successfully launch both Persuasion, version 2.12 and Persuasion, version 3.0.
We suggest that you upgrade the Duo 280c to version 7.5 of the system software, or consider upgrading the AppleShare Server to version 4.0.x or later.