Created attachment 3420 App menu button after log in Font hinting is not applied on the text in the panel plugins when the panel started at log in.
Created attachment 3421 App menu button pressed When the button is pressed you can see the font is hinted.
This most likely has to do with the double-expose problem (bug #6872), because it looks hinted/aliased, but drawn 2 times on top of each other. Could you try the patch in the commit below? http://git.xfce.org/xfce/xfce4-panel/commit/?id=23fa1aee1651f36c435c4867f09a718948d5c8fe
If you generate a tarball with a nano version for testing purpose I can install it (I still need to install a master version of Xfce somewhere).
Sure, but can't you build from master? You only need xfce4-dev-tools, everything else is the same as 4.8 branch.
If only need to overwrite the xfce4-panel binary sure. But I don't want to install in the system tree. I should install master in a dedicated prefix, but couldn't find the time to do it lately.
Still have to test just after log but seems fixed when panel is restarted in a running session.
*** This bug has been marked as a duplicate of bug 6872 ***