Passing the noapic option to the kernel was working until 2.6.25-13 kernel version.
From 2.6.25-14 version, it still works but it has the side effect of not power off the machine when halting the system.
It also dumps a (kernel?) trace, althogh it doesnt looks like a kernel panic. I only see few lines since I can not do anything in the system but switch it off with the power button.