As said on irc, please remove xulrunner runtime dependency. Neither gnash plugin nor lightspark one (other NPAPI plugin around?) depend on it at runtime. Browsers which use such plugins already depends on xulrunner.
Attached patch.
=== modified file 'control' --- control 2011-05-30 20:35:15 +0000 +++ control 2011-08-19 00:58:25 +0000 @@ -27,7 +27,7 @@ Package: icedtea-plugin Section: web Architecture: any -Depends: openjdk-6-jre, icedtea-netx (= ${binary:Version}), ${xulrunner:Depends}, ${shlibs:Depends}, ${misc:Depends} +Depends: openjdk-6-jre, icedtea-netx (= ${binary:Version}), ${shlibs:Depends}, ${misc:Depends} Conflicts: icedtea-gcjwebplugin (<< 1.0-1ubuntu4), icedtea6-plugin (<< 6b18-1.8.7-3) Replaces: icedtea-gcjwebplugin, openjdk-6-jre (<< 6b18-1.8.7-3), icedtea6-plugin (<< 6b18-1.8.7-3) Provides: icedtea6-plugin