I've attempted to jump start my X5 twice. Last year when my battery died and this morning when the battery was accidentally discharged. Both times I've tried to use the jumpstart (+) terminal and ground connection under the hood. And both times I could neither jumpstart or even charge the battery via this terminal and ended up jump starting by direct battery connections. I called my local bmw dealership and there is no know defect bulletin for this problem. Has anyone else encountered this?

Thanks,
John