There is a new source package version 1.0.5 for the zoom interpreter. This version requires expat 1.95.7 or later to compile. The source package can be found at: http://www.logicalshift.co.uk/unix/zoom/zoom-1.0.5.tar.gz http://www.ifarchive.org/if-archive/infocom/interpreters/zoom/zoom-1.0.5.tar.gz The current ebuild for version 1.0.4a is in "games-engines/zoom".
There's also a new beta version 1.1.0beta2 at http://www.logicalshift.co.uk/unix/zoom/zoom-1.1.0beta2.tar.gz
1.0.5 in portage. thanks for the bug report.