Have had the BB 8830 for approx 1 week (on Sprint network) have noticed that the calls received are approx 1-2+ rings behind that of the caller calling my device (example person A calls my device & on their end hears 1-2+ rings before my device even starts to ring). This happens regardless if this is caller id blocked call or not & ringtones are combination (depending on caller) of those that came with the phone or downloaded.
Also Bluetooth headset also seems to recoginze that i am receiving (ie i get a clicking my bluetooth headset prior to the audible BB device ringing)
make sure you have the latest software patch. You can find it on sprint.com/downloads. Then enter your make and model and i believe its the first one on the list. Good luck!