Huge letters in apps under fvwm2
I've just installed Slack 12.2.0 onto a Compaq 7300nx laptop (kernel 18.104.22.168-smp from the CD , X.Org 1.4.2, fvwm2 2.4.20). X resolution 1280x800.
If I run an application (Firefox, Seamonkey, Gimp, Skype) the app starts a in a (very) bigger window than the desktop and with HUGE LETTERS, so large that e.g. the word 'Bookmarks' is as wide as the physical screen.
Tried to google but haven't found relevant pages.
Thx in advance for any tips, explanations or (the best case) solutions,