Thanks for the info, I didn't know of XUL technical details. Still, if the issue is local to Thunderbird, it's still very likely a bug in whatever XUL uses to render via GTK. For example, LibreOffice tries to use GTK rendering too (GTK3 as of late) and it's not 100% compatible either. I'd try to bug Ubuntu Mozilla Team or maybe upstream developers directly. Just FYI, Murrine developer is <a href="https://launchpad.net/~cimi">https://launchpad.net/~cimi</a> -- Sergey "Shnatsel" Davidoff <div class="gmail_quote">2012/9/12 John Knight <<a href="mailto:john@classiccitytelco.com" target="_blank">john@classiccitytelco.com</a>> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div text="#000000" bgcolor="#FFFFFF"> Hi Sergey, Thanks for the response and for taking the time to look at the problem with me; very much appreciated. Respectfully, that doesn't sound correct though; XULrunner is a high level ui toolkit that binds to gtk2 (and also bind to cocoa and win32 for other platforms). Firefox and Thunderbird are still very much using gtk2 for their applications, they just aren't using c/c++ bindings but instead using crossplatform XULrunner (which can render using other toolkits making it cross platform) which in turn calls gtk2 to write the widgets to screen, as opposed to being a completely unique toolkit like motif or qt or using gtk2 directly. Here's the ticket tracking work Mozilla is doing moving from gtk2 to gtk3 for some time in the future, showing they are most definitely using gtk2 when rendering xul configurations fed into xulrunner on *nix platforms: <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=627699" target="_blank">https://bugzilla.mozilla.org/show_bug.cgi?id=627699</a> The only two themes that are problematic, Ambiance and Radiance, are each using the same Murrine gtk2 engine that Ubuntu ships. I recently discovered Clearlooks and all other gtk2 themes I load do not have the same issue as Thunderbird renders seemingly every other gtk2 correctly for the scrollbars. -John Knight </div></blockquote></div>