Hi!
I did have a lot of problem with 536ep winmodem. Now it is working. First of all the 4.62 driver doesnot work, try 4.60 instead. Make a clean install, I mean, go to your 536ep driver directory (that you have downloaded and extracted), do make clean, make 536ep and make install (as Root/ Su). Note that after you have done make install it ends up in an error messege 'cannot remove /dev/536'. Do a manual removal by
rm -f /dev/536ep
say yes to the next
then re-link /dev/536ep by
ln -sf /dev/536ep /dev/modem
Now restart your kppp and use /dev/modem as your modem and configure your dial-up.
Hope this helps
Santanoo