It's strange, firefox shouldn't detache from the console. Check if there is any running firefox instance.
And have a look at ~/.xsession-errors.
Ok you were right, firefox does not detach from console. I just caught this output. ------------------------------------------ 139 markus@zoidberg ~ % firefox Xlib: extension "RANDR" missing on display ":0.0". Xlib: extension "Generic Event Extension" missing on display ":0.0". Xlib: extension "Generic Event Extension" missing on display ":0.0". Xlib: extension "Generic Event Extension" missing on display ":0.0". Xlib: extension "Generic Event Extension" missing on display ":0.0". (firefox:10442): Gtk-WARNING **: Im Modulpfad »murrine« konnte keine Themen-Engine gefunden werden, Xlib: extension "Generic Event Extension" missing on display ":0.0". (firefox:10442): atk-bridge-WARNING **: AT_SPI_REGISTRY was not started at session startup. (firefox:10442): atk-bridge-WARNING **: IOR not set. (firefox:10442): atk-bridge-WARNING **: Could not locate registry [1] 10442 segmentation fault (core dumped) firefox ------------------------------------------ So firefox segfaults... hum very interesting. Markus