HTTPTracker::onDataRecieved store the data received from the tracker in
the variable "data". The newly received data is appened to the end of the
old data. But the size of variable "data" is never set to 0, when the data are used.
So on every request to the tracker, the newly received data will be appened to old data.

If the first response from the tracker was been "failure reason",
ktorrent won't be able to load the torrent unitl ktorrent is restarted.
It is not good, but the effect with using old peers can be worst.
Am I right? Am I missing something?

I use the SVN code from yesterday (29.10.2005)

You're right, I'll fix it with my next commit.

That's the third small bug you discovered, thanks for pointing them out, they could have been in there for a lot longer.