I just looked in the .xsession-errors and the last entries look like this:
[FVWM][GetWindowSizeHints]: <> The application window (id 0x2404285)
“Information - Konqueror” has broken size hints (max_width).
fvwm is ignoring those hints. If you are having a problem with the
application, send a bug report with this message included to the
application owner. There is no need to notify mailto:firstname.lastname@example.org.
hint override = 0, flags = 23f
min_width = 351, min_height = 106, max_width = 350, max_height = 105
width_inc = -1073749256, height_inc = -1073749576
min_aspect = -1226282172/148456960, max_aspect = 148437344/-1227035417
base_width = -1222019472, base_height = -1222019472
win_gravity = 1
[FVWM][style_parse_and_set_window_style]: <> Bad style option: WindowSkipList
[FVWM][Read]: <> file ‘/ect/X11/fvwm/menudefs.hook’ not found
[FvwmIconMan][FlocaleGetFontSet]: (--fixed-medium-r-normal–13-) Missing font charsets:
[TestPager][FlocaleGetFontSet]: (5x8) Missing font charsets:
JISX0208.1983-0, KSC5601.1987-0, GB2312.1980-0, JISX0201.1976-0, ISO10646-1
It seems to have something to do with FVWM, but I have no experience with these kind of errors.