Regular iCal reminder message?

Hi. I have a reminder set up in iCal so that a message appears telling me to attach my Firewire drive once a week so I can run a full system backup using SuperDuper!. However, I have to change the date every week, as iCal won't let me specify that I want this reminder to appear on every Friday of the week ad infinitum - I have to specify the exact date. This is kind of a pain.

Does anyone know if there's a way to have this message appear regularly without having to change the date?

Thanks.

PS: the reason I disconnect the Firewire drive is that it kicks in whenever the kids switch to their account from mine, and visa versa, and that bugs me no end.

Do you have it set up as an event that repeats every week? If it is a recurring event and you try to set a reminder for one of them, it should ask you if you want to change all events or just the one. Simply click 'All' and it should remind you every week.