When I launch Minecraft and head over to "Multiplayer", the any server entries I have added will display "Can't reach server" where the MOTD is usually displayed. I'd have to wait a few seconds, and hit "Refresh" to recieve the server status and MOTD. After hitting refresh, things become normal again.

The stranger thing is that I recently found is that my internet connection is interrupted when I enter the Multiplayer screen. I've run Minecraft a few times, and my internet /only/ interrupts when Minecraft is retrieving server info. I've only seen this with 1.6.2, 1.5.2 works as expected. There isn't an error message to show.