OMG THE EDITS!!
Interesting problem, i will admit. try deleting the servers.dat file completely, going into multiplayer, and then save a new server. close the client and reopen. does that work?
If no, try deleting the entire .minecraft folder (not just uninstall) and re-download/install it
Yeah I thought it would be better to edit than post a heapo times and risk it being considered mass bumping
What you said half worked, my server stayed there after a restart of launcher and client but after on that restart I added one more and restarted again. This time only the TeamExtreme IP and my first added server remained.
If it is just me having this problem then I will reinstall but I think that the "file" that is making the Team Extreme IP appear is editting the server.dat files and this is affecting whether they save or not. I will have to do some more testing to get better evidence on when it occurs.
Oh and I liked you "How did you find out about us"