I have two laptop users and each has their own BlackBerry. Each person has a barebones desktop in the office to handle redirection and they use their laptops for Intellsync. An error creeps up every once in a while where Intellisync fails in the middle of a sync. An example of the error is attached. It occurs around the time the calendar is trying to sync. This error has occured on various versions of DM from 4.x up to 4.2.2. Reinstall of the DM software fixes it for a while, but the error always comes back.

I was wondering if the issue may be caused by a BlackBerry being associated with two computers... a desktop for redirection and a laptop for Intellisync.

this usually indicates a hardware error on the PC, download memtest and let it run for a while, see what happens