Sony Ericsson GC75 GPRS pccard modem

I just got a Sony Ericsson GC75 GRPS pccard modem.  It seems to look
like an ordinary modem with "at" commands to the system, so the
regular serial driver "just works" (BTW, I'm running 4.5R on an IBM TP
570.):

  /kernel: pccard: card inserted, slot 0
  pccardd[56]: Card "Sony Ericsson"("GC75 PC Card") [ML2029] [(null)] has function ID 2 
  /kernel: sio1 at port 0x2e8-0x2ef irq 11 flags 0x40000 slot 0 on pccard0
  /kernel: sio1: type 16550A
  /kernel: sio1: unable to activate interrupt in fast mode - using normal mode
  pccardd[56]: sio1: GENERIC PCMCIA modem inserted.

I have no clue what the message about not being able to activate fast
mode is about.  Do I need to worry?

Talking to the card directly using the cu program and issuing "at"
commands works.  I have however not yet managed to establish a PPP
connection over it, but I think it's because I need pap authentication
info from my provider.

There is one strange thing happening with the system after I have
removed the card.  Inserting my regular Ethernet card (3Com 3C574B)
afterwards works fine, but when I then do "pccardc power 0 0", the
system hangs and beeps continuously until I eject the card.  The
system then seems fine and has not crashed.

The manual for the windows software that comes with the card gives the
impression that it can monitor the GSM signal level and various other
stuff while you are connected.  This would be very handy to have on
FreeBSD too.  There are "at" commands to retrieve this information,
but when ppp is running you can't issue those (or can you?).  I am
wondering whether the card has some additional registers that can be
read?  I attach the dumpcis output so someone more clueful perhaps can
figure this out.

A possible pccard.conf entry to add (maybe remove "ML2029"?):

# Sony Ericsson GC75 GPRS PC Card Modem
card "Sony Ericsson" "GC75 PC Card" "ML2029"
	config	auto "sio" ?

Cheers,

Bengt