Grsecurity-2.6.32.9-201003071225 reboots continually (AMD64)

[specs]

When I upgraded from 2.6.32.8 to grsecurity-2.6.32.9-2010071225 I found the machine continuously rebooting.

Vmlinux, config and log of the bootprocess: http://www.aoi-karin.net/grsec

After the problem I tried:
grsecurity-2.1.14-2.6.32.9-201002231820.patch (success, without serial console)
grsecurity-2.1.14-2.6.32.9-201003071225.patch (fail, with and without serial console)
grsecurity-2.1.14-2.6.33-201003071645.patch (fail, without serial console)
grsecurity-2.1.14-2.6.33-201003112028.patch (fail, without serial console)

Things changed between the 02-23 and the 03-07 version:
- added serial console (to be able to produce a logfile)
- activated the CONFIG_GRKERNSEC_AUDIT_PTRACE option

Small addition:
disabling CONFIG_GRKERNSEC_AUDIT_PTRACE makes no difference

[specs]

Since the log ends with loading ACPI-modules I tried to see what's there if ACPI is not available in the kernel.
Without ACPI the last message before rebooting is:

Waiting for /dev to be fully populated...

(/etc/init.d/udev)
Tried the above with the latest stable grsecurity patch (2.6.32.9-201003112025).

Since it seems to work with a timeout I have been thinking about some kind of watchdog error. However the only watchdog function available is CONFIG_CLOCKSOURCE_WATCHDOG, the general CONFIG_WATCHDOG is not set (but some thermal options are).

I have no ideas where to look further, but since the init is started it leaves room for adding an init-script.