[SyncEvolution] evolution and CalDAV calendar: authentication

Hello, I use syncevolution to sync my local evolution client to a funambol server. This worked fine until today. I've added a new calendar of type CalDAV to evolution. When I run syncevolution now it tells me: "Synchronization failed" and "calendar: opening calendar: Authentication required". I understand that it's not possible to sync this new calendar without authentication but I don't know how to set things up: Either I could disable the respective calendar: how can I do that? Or i could supply username/password to syncevoltion: how to do that? Or I could remove this calendar from evolution alltogether - which I don't want to do. Any suggestions? thanks, stephan