serial console fails after intr_establish

Hi!

I'm seeing a strange bug on NetBSD/sandpoint since I tested recent
kernels on it (NetBSD6 works). The serial console stops working at
the first intr_establish() call, and continues working after going
to multiuser with interrupts enabled.

Booting on a LinkStation HD-HLAN looks like this on the serial console:

NetBSD 6.99.27 (KUROBOX) #4: Sat Nov 16 12:06:14 CET 2013
	[email protected]:/home/frank/netbsd/current/src/objsand/sys/arch/sandpoint/compile/KUROBOX
Model: kurobox
total memory = 65536 KB
avail memory = 59436 KB
OpenPIC Version 1.2: Supports 1 CPUs and 26 interrupt sources.
mainbus0 (root)
cpu0 at mainbus0: 8245 (Revision 0.4), ID 0 (primary)
cpu0: HID0 0x90c000<DOZE,DPM,ICE,DCE>, powersave: 1
cpu0: 195.12 MHz
eumb0 at mainbus0
com0 at eumb0 unit 1: ns16550a, working fifo
com0: console?Sat Nov 16 12:07:51 CET 2013
Starting root file system check:
[...]

There is a strange character after "com0: console" which makes we think
that the port has been reinitialized at a different speed?

But this happens definitely during a call to intr_establish(), and there
is nothing which should change the port speed.

When I remove the intr_establish() in sandpoint/com_eumb.c the
output continues, until the next intr_establish()!

Has anybody an idea what might have changed to cause such a behaviour?

-- 
Frank Wille