Accurately tracking all active touches?

I found that sometimes the number of touchesbegan touches does not correspond to the number of reported touchesended/touchescanceled touche开发者_如何转开发s, leading to reported touches thats no longer active but never are reported as dead.

This happens if the user is cluttering the screen with touches, perhaps by putting their whole palm on it or melting two or more fingers into one touch. Not sure why it happens, but a number of users has sent me a report of the opengl based interface in my app freezing because of it. I put in a workaround which eliminated the issue, but i wonder if there is a way to accurately track all active touches?

Basically I want to maintain an array of UItouch pointers pointing to all fingers currently touching the display at any given time. Making sure the array is always empty if the user is not touching it, no matter what crazy things the user did.

Anyone else noticed this? Any ideas on how to solve it?