5.3-BETA3 serial console

Hi List,

I recently upgraded from 5.2.1 to 5.3-BETA2 and on 6th of September to 
5.3-BETA3.
I have a problem while trying to enable the serial console. I just 
change the line:
([mhettwer_at_ares] <~>)$ cat /etc/ttys |grep ttyd0
ttyd0   "/usr/libexec/getty std.9600"   dialup  off secure

from "off" to "on" and issue a "kill -HUP 1" to initalise the serial 
console.
After doing the SIGHUP I get a hardlock. Unfortunatly the Kernel doesn't 
break into the debugger... it's just frozen ... no input possible, and 
of course, no serial console available either.

Some info's about the System I use:
([mhettwer_at_ares] <~>)$ uname -a
FreeBSD ares.meganet.local 5.3-BETA3 FreeBSD 5.3-BETA3 #0: Mon Sep  6 
14:58:58 CEST 2004 
mhettwer_at_ares.meganet.local:/usr/obj/usr/src/sys/GENERIC  i386

Of course, GENERIC runs with all debugging options, nothing changed by 
myself.
The only way to boot my laptop (Fujitsu Siemens Lifebook C-1020) is with 
acpi, and it looks good. See my dmesg output at 
http://www.unixoid.de/freebsd/dmesg-5.3-BETA3.txt

Same problem occurs when doing a "tip com1" as root. Hardlock, no 
debugging prompt :-/

Well, is there any way to get more information ?

By the way: The rest of 5.3-BETA3 is doing a great job. No problems in 
daily work yet. Unluckily I desperatly need my serial port.

Any help greatly appreciated!

Best Regards and keep up the good work,
Marian