During FreeBSD 5.2.1 installation on my first laptop (Toshiba A40-221) the following lines appears as the OS gets ready for the installation:

acpi_tz0:<thermal zone> on acpi0
pcib0: <ACPI Host-PCI Bridge> port 0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0

and then the installation pauses; it sticks exactly at these lines doing nothing else.
I don't know a lot of details about computers and i am not a FreeBSD expert, so i can neither interpret this message, nor fix it.
Can somebody explain me what's the problem and what can i do to fix it?

something to add:
i've tried to boot having ACPI turned off, but it didn't work. The 3 last lines where :
"pci0:<display> at device 2.1 (no driver attached)
uhci0:<Intel 82801DB (ICH4) USB Controller USB-A> port
0xcfe0-0xcfff irq 10 at device 29.0 on pci0"