Half Ring on CallerID Blocking Apps - A workaround
This "half ring" issue is common to almost every Call Blocking app. I believe it's because the ringtone activates on the first received ring pulse while the CallerID info arrives between the first and second ring pulse...
So, a partial ring is initiated before the app recognizes it should block the call. If your particular ringtone happens to have sufficient null audio in the beginning (no sound) then you won't have this problem. Different ringtones behave differently depending on how soon the audio begins on them.
If you're getting that pesky half ring, one workaround might be to customize your ringtone to start with 1 or 2 seconds of silence followed by the rest of the desired wav. Several ring tone makers/wave file editors are available for your PC.
I used my Nero audio editing software and inserted about one second of muted audio to the beginning of my favorite ringtone. Then, I sent it back to my BB and selected it as the ringtone for my Normal sound profile.
Now, although the phone IS actually ringing for a split second before the Call Blocking application recognizes the need to block the call, it can not be heard (it's playing the silent portion you've inserted at the beginning).
So, there's a workaround for those of you who find that split second of ringing to be annoying. Of course, if your sound profile includes "vibrate", there's little one can do to suppress the vibration other than shutting off that feature in the profile.
ADDITIONAL FINDINGS AND WORKAROUND for HALF RING
UPDATE - ADDITIONAL FINDINGS:
Originally Posted by toytooii
1. Using Call Blocker Pro, I have noticed this half ring issue to be less of a problem when compared to some other apps (both free and $$). Using the same ringtone (unmodified) I do not get the half ring with Call Blocker Pro but do with some other apps.
2. Regarding Vibrate
If the sound profile includes vibration, you will not get any hint of vibrating on a blocked call if you set the "Vibrate with Ring Tone" option to "ON". (tested only on Call Blocker Pro)