Just to let you know, I have had problems under windows 98 myself, however run it fine on a Windows 2000 machine and linux. If I find a solution, I will let you know, but the steps that I tried to follow were located at:

http://black-widow000.150m.com/TiVo-PPP/

Hope this gives you a leg up and If you can get it working, I would be interested in how you did it!