I have been using Blogrolling.com to manage my blogroll (on my right hand side bar). Quite recently, I realised that some of the links are dead. It was only then that I realised that we can only add but cannot delete the dead links from the blogroll - in fact, I can edit it at all.
According to their blog, their site was hacked late last year and they took the "system offline to ensure that no customer data was compromised". Right now they are in the process of developing a new blogrolling system. It's quite frustrating but I am sure it will be worth the wait.