This is jujst something I noticed after poking around with kazaa and it always helps me connect to multiple sources. If Im mistaken on the technical side dont flame me, it works for me.

When you set the max number of sources per file to 8 for example. The dat file will have 8 available slots to store the IP user info, now when these get filled there is no space to store new connection (this is from observation). Upon opening these files in kDat I noticed that a lot of slots read "not stored" or have no file id, i just delete these thus opening new slots for new connections. I've messed around many time doing this and right after doing so, my previously mediocre download get new sources (after another search and jumping several SNs). Now I have my max sources per file set at 150 and I clean out my dats daily.

Hope this helps.