double pings?
After my zalary-love and several other people have mentioned that they have accidently double pinged me with Trackback (MT 2.21), I posted a thread on the forums to ask about it [more details on it in the thread]. Ben says that the sending server probably is timing out too fast, and you can add a line to your mt.cfg file (PingTimeout 20) to increase the amount of time it takes.
This won’t help pings you are RECEIVING, just pings you are SENDING. So if you are accidently sending a lot of double pings, you might try this fix and see if it helps.