Wouldnt be beneficial if in one of the upcoming updates RIM added a "bi-weekly" recurrence option in the calendar app, i dont know how many users think thats important but i think its a must... unless im just dumb and dont know a way around it other that setting it individually.
It does work, in fact they've mimicked what Outlook uses and let you pick the days of the week it occurs on and how many weeks pass between occurrences.
You need to set the recurrence to Weekly and you can then click on the days of the week it occurs. The "Every" variable is how many weeks should pass between occurrences.
Give that a try, it should take care of the problem. Also as an FYI I'm on .109 in the event you're on something older and this has been added in the later betas.
Happy to help, it took me a while to find it the first time I went looking as well. I think "reoccurs on __days and __days" and look under daily recurrence, but I guess that logic is flawed since they put it in the weekly recurrence section.