Most networks are notoriously off their numbers. There are only few that I've seen that actually track every subid every-time, Hydra used to be one of them. Almost all of the DirectTrack networks have click drop-off, and some other notable networks on their own platforms.
Which networks are you using drop-offs from?
There is a-lot of click fraud going on right now all over the place. Many of the click-fraud bots only click through the first page and leave, with tracking202's cloaking that means most of them don't real the real-outbound page (the network in this case) if it's fraud traffic.
I'm not saying it's not p202's fault, but its a combination of factors from bad traffic, to networks dropping a few clicks, and p202 could potentially be slow, but as long as u guys test it and see it's fast then you know it's working. T202 is showing the clicks, and your redirects I assume do work every time you click on it, so your visitors SHOULD be redirecting through.