I was able to reproduce the bug you just described. Can you please file a new bug report for that? Thanks!
** Changed in: file-roller (Ubuntu) Status: Incomplete => Fix Released -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to file-roller in Ubuntu. https://bugs.launchpad.net/bugs/646554 Title: Won't add files to JAR unless renamed to ZIP extension -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs