not to start one of those wars but LXDE is rubbish, use XFCE (which I assume you meant when you posted XFDE) every single annoyance in LXDE (and there are a big ole pile of them) is corrected in XFCE, and if your wanting a middle weight desktop (compared to ICEWM or something) its just one less pain in the ass
IIRC it uses Fluxbox as the WM.
no is uses LXDE, hince the name ]