Hoping that this post can help someone.

I inherited a Dell Inspiron 9100 with an internal Winmodem (Broadcom 82801EB/ER (ICH5/ICH5R) 'AC97 Modem Controller) and wiped Windows and installed SuSE 9.1 with kernel 2.6.11. The device is automatically picked up but didn't work with Kinternet. This has been a real pain in the arse. I've learned there is a whole class of "WinModems" that transfer the digital signal processing work to the host CPU (HSP = Host Signal Processor), whereas only 5 or so years ago many modems did all/most of the processing. As per
www.linmodem.org, I downloaded scanModem.sh and ran it, it provided good advice, i.e download slmodemd and run these commands (as root):

# modprobe snd-intel8x0m
# slmodemd --alsa -c AUSTRALIA modem:1

The first loads a sound related kernel module, and with the SmartLink modem daemon running, wvdial can then be run by smpppd. I would run these two commands, and then start Kinternet and the log file for pppd would almsot always say that the modem could be initialised but that it could not obtain a carrier. Except once, when wverything worked fine. I then suspected some kind of interrupt issue, and after trying lots of things (e.g. apci=noirq in the grub boot script menu.lst, adding X3 to the list of initialisation strings for the modem via YAST, etc), I ran wvdialconf wvdialtest.txt but even though I had set up the modem in YAST, I checked /etc/wvdial.conf and all the user settings (e.g. dial in number, username, password etc) were empty!. I added these as well as Carrier Check = no as suggested by the slmodemd README, and that's when I got the lone connection success. By the way, another thing I tried (someone online suggested this), to use an older version of slmodemd (2.9.6 as opposed to the one I'd installed, 2.9.10), but that didn't work either. I also tried removing the oss module as suggested in Slmodem-ALSA.txt, to no avail.

In frustration, I went and purchased an external USB modem but couldn't get it working (I had purchased on the proviso from retailer that I could return it if it didn't work)! Then finally as a last ditch I used # slmodem --help and noticed the "-r, --ringdetector with internal ring detector (software)" option, tried it and it worked! However there is no sound during dial-in, and establishing the connection continued to be flaky. So I followed the advice in the wvdial.conf file supplied with slmodemd, i.e.

Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
# Lack of dialtone acquisition can be due to low line voltage,
# a common problem in Italy.
# Try inserting a "dial without waiting": X3
# Init2 = ATQ0 V1 E1 S0=0 X3 &C1 &D2 +FCLASS=0
# In case of connection instabilities, specify a lower frequency:
# Init2 = ATQ0 V1 E1 S0=0 X3 &C1 &D2 +MS=34

I did both of these and now everything seems to work reliably.