This bug looks like some GTK+ bug. It was reported on sourceforge for gnusim8085 (http://sourceforge.net/tracker/index.php?func=detail&aid=1556427&group_id=86462&atid=579699)
We developers closed the bug with 'WORKSFORME' status at that time since we were using Dapper (GTK+ 2.8.x). The reporter was using Gentoo with GTK+ version 2.10.3 -- "About"-window cannot be closed with "close" button https://launchpad.net/bugs/64206 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
