I have had my new Curve 8530 for about 3 weeks. After the first week of ownership my daughter and son-in-law told me some of my bbm came through multiple times. I figured out this only happened when I was at home. It just so happens that is the only place I used WiFi was when I was home. I would link to my house WiFi. I had contacted verizon and after going through everything we deducted that it was either the WiFi or it was a blackberry problem as everything on Verizon's side was ok. I tried turning my WiFi off and this did the trick. I have since turned my WiFi off permanently because it just isn't worth the hassle. If anyone else has had this problem or know of an answer, please let me know.
I agree with you that was the problem. WiFi should be left off unless you are in a place where you do not get a 1XEV signal. You will find that your battery will last a lot longer between charges.