The server list is deleting itself

My server list is deleting itself sometimes when I refresh

What I expected to happen was that the server list should refresh as normal when I pressed the "refresh" button

*What actually happened was that when I pressed the "refresh" button, my server list dissapeared, and I have to add all the servers to minecraft again. This has happened before, but only in minecraft 1.7.4. It dosn't happend every time I refresh, but sometimes.

Steps to Reproduce:
1. Launch minecraft 1.7.4
2. Press the "multiplayer" button
3. If you do not have a server added, add a server
4. Click the "refresh" button to refresh your server information
5. It doesn't happend every time.

PS: I couldn't fint the 1.7.4 verson in the verson selection. I chosed 1.3.7, but my verson is 1.7.4