The server.dat file located in the .minecraft folder gets renamed to server.dat_tmp upon refreshing it too fast. Just rename it back to server.dat and you will get your serverlist back.
This problem is still occuring in 1.8
64x64 = 64 x doors
No wonder it crashes, also this is not the right format.
How to solve:
1) Pause menu2) Options...3) Video Settings...4) Graphics -> Fancy
The server.dat file located in the .minecraft folder gets renamed to server.dat_tmp upon refreshing it too fast. Just rename it back to server.dat and you will get your serverlist back.
This problem is still occuring in 1.8