I recently purchased a US Robotics 5610 modem under the promise of finally being able to connect to the internet in Linux. I run an Athlon XP 1900+ with 512Mb ram and dual boot between a harddrive install of Knoppix and WinXP. Windows recognized the new modem as a PCI serial adapter, and would not find drivers for it, but a forced install of the native Windows drivers rectified that problem and it runs beautifully in Windows. The modem did not come with a driver disc or books, and lspci says this:
# lspci
0000:00:0b.0 Serial controller: 5610 56K FaxModem 56K FaxModem Model 5610 (rev 01)

As you can see, I don't think it is recognized right away as a modem, but i am just a n00b...

I followed a How to found at www.math.sunysb.edu/~comech/tools/PCImodems.html
and did this (I changed S3 to S4 because my modem shows up on com 5 in windows.)
# cd /dev; test -c ttyS4 || ./MAKEDEV ttyS4; chmod 666 /dev/ttyS4
# setserial /dev/ttyS4 uart 16550A port 0xbc00 irq 12 baud_base 115200 spd_vhi skip_test
# ln -sf /dev/ttyS4 /dev/modem

And so when i run the config in kppp, it tells me it either cannot create a modem lock file, or the modem is busy, wether I choose /dev/modem, or any of the com ports.

I know this is a n00bish question, so please do not flame my n00bness , and any help is greatly appreciated and will be repaid with a cookie eaten in your honour.