First, a heads-up that Opera doesn't support the bibtemplate structure at all. I believe that's due to Dojo only officially supporting Opera on dojo core, not the dojox extensions. Probably not a huge concern with Opera hovering around 2% of browser market share, but when I'm browsing the Web on my Wii it would be so nice to have item details displaying properly... heh.
Second, a slightly more obscure but also more serious bug (based on browser market share) is that Internet Explorer (6,7,8) don't support one of the advanced bibtemplate features; check the URL display for items that have located URIs; in IE, the URLs that are displayed always come from the bib record, rather than from the asset.uri table. I don't have a test case ready at hand, unfortunately, as I'm on leave at the moment, but it should be pretty easily reproducible. The item details template that we're using can be seen at http://laurentian.concat.ca with the most pertinent source at http://svn.open-ils.org/trac/ILS-Contrib/browser/conifer/trunk/web/opac/skin/default/xml/rdetail/rdetail_summary.xml An aside, Safari (at least on Windows) and Chrome / Chromium seem to work with bibtemplate just fine.