By "50% of my mail being delivered", I didn't mean old or new. It appears that approximately every other message is being delivered.
Actually if I look at today's mail (approx 16 msgs) it in fact delivered every other one (msg #1, 3, 5, 7, 9, etc.). I checked to make sure it is not a pattern, and it is most certainly not.. messages came in spurts of 2 at a time last night and again this afternoon. But most of the time I get about 1 of 2 messages sent to my BB.
Will try a battery pull now.. not sure what else to do!