Font reset by Preferences.
Status: Beta
Brought to you by:
nemesis_xpn
In the article pane, click the '-' button to "Hide Headers" then press Ctrl+F to select "Fixed Pitch Font". Now, click on the "Preferences" button on the toolbar and, without changing anything, click the "OK" button.
Now the text in the article pane has returned to the default(?) proportional pitch font and the headers are expanded. Ctrl+F now works in reverse: pressing it - to *deselect* "Fixed Pitch Font" - actually restores it.