Freezes up every time I join a server

Every time I attempt to join a server minecraft freezes up on the "Logging in..." screen, and eventually says not responding, etc. After quite a while of waiting, my client reports "disconnected by server, ReadTimeoutException: null." With a back to title screen option. The funny thing is, I was just playing on a server for about 30 minutes when I decided to pay a visit to my single player world. Shortly after that I start getting this error. About to update to Java version 7 update 25, will check back if this is still a problem when this is completed. After updating to a current version of java, this problem is still reoccuring. Also, after starting up a server using a localhost ip, this is still a problem, even though the server version is 1.5.2.