To better assist you, what os is your tour running? What version of desktop manager are you running?
Try syncing only one of the 3 first. Also what calender are you trying to sync? Yahoo was working for me but as of late it has stopped saying yahoos server has not responded..
Check which is your default calendar - that is a confusing aspect - there can be multiple calendars (on BB, Menu, Scroll to find the place to show or change calendar). Only one of them syncs with Outlook but others are more knowledgeable of this issue than I am.
i have the same problem. it happened to me once before, and the fixes above worked for me. However, when I upraded to 5.0 OS, it stopped syncing the calendar again. I just started using google sync instead. It works effortlessly and syncs wirelessly. Plus I can use it to sync to my icalendar on my new mac. works great.