Dont worry about BIP settings as the ion board doesnt have it anyways.
You said "it will fire single to five balls....", does this meen you shot slowly 5 balls and non broke or does it meen you can shoot upto 5 balls per second approx then it soups?
If it meens you can shoot say 5 balls slowly without any breakage then once again my guess is brittle paint or the barrel to bore match. When your daughter puts the balls down the barrel do they pretty much just roll out then end with no force or anything?
Once again are the eyes on? You know they are if the light blinks quickly when a ball is in the breach or if the marker is empty it wont fire but the power light blinks once per second or so, if they are off the light will just blink twice fast every second or so.
Next have you ever chronographed the marker? If not it could be you have the velocity to high.
Before you do anything really i would get a brand spanking new battery either a duracel or energizer ultimate (silver and blue energizer) and put that in then try it. Lots of times its simply because the battery is going dead or the board simply does not get enough power.
If you can get another brand of paint even just a few balls or so just to try and see if its just the balls. Another quick thing to make sure you clean your barrel out probably (look down it and it should be nice and sparkling) as old paint or whatever in there will cause breaks to.
Try the above if you can then post back up