... it's a bug of "PCManFM".

With PCManFM 0.9.8 within Knoppix 6.4.4 I get the same result, if I select 'Extended/ show Menu..'

Changing the value of "show_wm_menu" from "1" to "0" in
'/home/knoppix/.config/pcmanfm/LXDE/pcmanfm.conf' and re-login, I get the old behaviour.

Greetings Werner * http://www.wp-schulz.de/knoppix/summary.html
Own Rescue-CD with Knoppix (Knoppix V6.4.4 remaster)