For some reason chuncks don't load until i get really near them. If I'm not wrong they do load with time, but it takes way too long. This bug makes playing for example the "15 Seconds" map by SethBling almost impossible. I recorded a video (http://youtu.be/9QGt_tkRCXE) showing the problem. I tried to search for this porblem but didn´t found my problem.

Edit: I added the complete output that Kumasasa requested. I didn't know if i had to do anything while minecraft was on so i played the "15 seconds" map again for a bit.