text displayed in the header line with wrong faces

[Ernest Adrogué]

Hi there,

Face attributes appear to be interpreted differently in the window
header line than in other parts of the window.  For instance, if I
evaluate

(setq header-line-format
      '(:eval (propertize "abcdefghijklmnopqrstuvwxyz"
                          'face 'show-paren-match)))

the text in the header line is displayed in what seems to be reverse
video: http://i.imgur.com/BU0XmGm.png

This doesn't happen if I disable the theme that I'm using (namely
solarized, which can found here:
https://github.com/sellout/emacs-color-theme-solarized/).  Without a
theme, background and foreground colours are not swapped, although I
noticed that then the foreground colour property is not inherited.

Any pointers on what could be causing this?

Cheers.