yet another newbie ppp/modem question

[Alex]

I'm having some trouble getting my modem up and running on
FreeBSD 4.8. A search through the mailing list archives shows
that many of the problems I've been wrestling with seem to have
cropped up before, yet I  haven't been able to follow any of the
discussion to a workable answer.

My modem is sitting on cuaa2 and I needed to re-compile my kernel
to recognize that port. I did this and everything went fine,
although I am getting the dreaded "sio5: configured irq 2 not in
bitmap of probed irqs 0" error which I haven't found a solution
for in any documentation or discussion.

Just for laughs, I went ahead and tried to contact the  modem via
ppp, but when I enter the "term" command I get:

"Warning: deflink: /dev/cuaa2: Bad file descriptor Failed to open
/dev/cuaa2"

I am now officially stuck  and am entering a plea for help.

The relevant lines from the kernel config file are pasted below.
This looks right to me, but if anyone can think what I'm doing
wrong (including RTFM references)  I would be forever grateful.

Thanks, Alex

***************

# Serial (COM) ports
device		sio0	at isa? port IO_COM1 flags 0x10 irq 4
device		sio1	at isa? port IO_COM2 irq 3
device		sio2	at isa? port IO_COM3 irq 5
device		sio3	at isa? disable port IO_COM4 irq 9