Yeah, don't use both. If you have no need for "live sync" of calendar or address book I would just get rid of Redirector (it's stupid anyway because you have to leave it running all the time) and use BIS alone. That will give you email with wireless sync for that and you can plug in to Desktop Manager and sync via cable for Calendar, Tasks, Contacts on a daily or whenever basis, based on your needs. Must smoother and less "resource intensive"... (i.e. you can turn off your office PC at night and not worry about not getting your email if it accidentally get's turned off or if you close our Redirector.)
BTW, RIM is having some BIS issues today so if things don't work right with email coming to your BB it's probably because of that. Just FYI.