Finally, finally, I've conquered the Lawson Ticket system. The trick is to say way far away from the complicated and confusing web page and to go use one of the "Loppi" machines in the convenience store itself.
Loppi does a lot of stuff - dispenses event tickets, tops up phone cards, even makes out cash loans. All I really cared about today was getting tickets to Earth Celebration and Kinseees.
At the machine, you can enter the L-code if you know it and jump directly to the ticket purchase, or if you don't know the code, you can search for the artist's name or the date of the event. You can pay with a variety of Lawson-based credit cards, or type in your name and phone number and receive a slip that you take to the register and pay. The cashier trades your cash for computer printed tickets and you are done.
I know I'm probably the last person in Japan to have figured this out, but I'm glad I did. It's been one of those niggling "I know I can do this, but argh!" hurdles for a long time.
just wanted to let you know was happy to found your site, and going to go trough it, very interesting.