For the 1st time I'm able to boot Slitaz into VirtualBox without any problem. However once the graphical environnement is started I dont have any menu or taskbar. I'm just able to do ctrl+alt+F1/ctrl+alt+F7 to switch on/back to/from command line.
@TomG: Harald already reported this error of lxpanel segmentation fault in VirtualBox on the mailing list. The solution he has proposed is to remove the battery plugin. Hope it works for you too.