jar fails to execute natively

[Will Morton <macavity@well.com>]

I've created a debian package for my java application using
javahelper.  Everything seems to go ok, it installs the application
jar into /usr/share/<appname> and creates a symlink from
/usr/bin/<appname> to the jar, but this fails to execute with the
following error:

/usr/bin/robonobo: line 1: PK  : command not found
/usr/bin/robonobo: line 2: �� =: command not found
/usr/bin/robonobo: line 3:�� =� n� D  META-INF/MANIFEST.MF��1O�0 ���:
No such file or directory
/usr/bin/robonobo: line 4: syntax error near unexpected token `)'

I have jarwrapper 0.28 installed, so shouldn't this jar 'just
execute'?  Any idea what step I might have missed?  I am running
Ubuntu Lucid.

Cheers

Will