When I try to install debain 4.0 as guest on my laptop (HP Pavilion DV9205ca RAM=2GIGs) running Virtual Box on WinxP Prof. The boot sequence will hang from time to time. Sometime, entering DEBUG_BOOT=3 as parameter will sporadically result in a successfull boot. The kernel hangs with the message
Freeing unused Kernel memory: 256K freed.