This is a problem with the internet and happens to me and my friend. He can't connect to me but I can connect to him. Again this is just a problem with your internet setting with your computer.
Before you tried playing your world in 1.7 did you play in 1.6.2 or 1.6.4? because if you played in 1.6.2 and never updated to 1.6.4 that could cause rendering issues to you world and your world could be corrupt.
this is not a bug but a feature
ok I was trying in a desert. Thanks for the help