Ok so here's the deal:

I use the classic theme.

In Galeon, which I have been using for a very long time, there was (after some update a long time ago) a 'Mark forums read' button/link on the line with 'UserCP FAQ' etc.

Then I switched to Firefox a few days back. With Firefox there's no 'Mark forum as read' link at the top line, now it looks as it used to do a very long time ago (in Galeon too): There's just a 'Quck Links' pull-down menu which I have to use to find the 'Mark forums read'. This is much more cumbersome.

What I can't understand is why the layout of the forum is different in different browsers, when using the same theme?