sio problems

I have a Soltek MB with a Celeron CPU which I use for FreeBSD 7 testing.
Recently I wanted to use the serial port to communicate with a gsm phone. To
my suprise this did not work and odd errors were reported - like phone not
connected when the phone could tell me there was a connection.

[esbjerg_at_bishop]% uname -an
FreeBSD bishop.xbsd.net 7.0-BETA2 FreeBSD 7.0-BETA2 #0: Sun Nov  4 15:17:28
CET 2007     root_at_bishop.xbsd.net:/usr/obj/usr/src/sys/GENERIC  i386

I looked at the boot messages and saw:

sio0: configured irq 4 not in bitmap of probed irqs 0
sio0: port may not be enabled
sio0: configured irq 4 not in bitmap of probed irqs 0
sio0: port may not be enabled
sio0: <16550A-compatible COM port> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
sio0: type 16550A
sio0: [FILTER]
sio1: configured irq 3 not in bitmap of probed irqs 0
sio1: port may not be enabled
sio1: configured irq 3 not in bitmap of probed irqs 0
sio1: port may not be enabled
sio1: <16550A-compatible COM port> port 0x2f8-0x2ff irq 3 on acpi0
sio1: type 16550A
sio1: [FILTER]

I google for a while but without much luck. 
I have checked the BIOS settings which are irq 4 and 3F8 for port 1 and irq 3
and 2F8 for port 2. This should be correct but still FreeBSD reports
otherwise.

I suspect this has something to do with acpi(?).
Could anyone give me hints on how to debug and correct this problem?

--
Sven Esbjerg