Whenever I buy an itinierary on NW that includes any or all DL flights, I can never check in and print boarding passes from home on either the DL or NW web sites.

When I try to use the DL machines at the airport, they always tell me I must see the ticket agent. When I do that (after waiting in long lines), everything is fine and I get my boarding passes.

Have any of you had this problem? Do any NW/DL employees or other experts have any advice on how I can correct the problem?

Thanks and Merry Christmas!

Big Red Bill