I see this all the time on SG. Main map and wilds. Traveling, breaking a block, opening a chest, chopping wood, etc. causes all or part of the area to not be rendered (all I see are block frames when a block is highlighted. It is a great cheat to see what is under ground, but makes for lousy video and makes it difficult when you can't see where you are going. I usually play between 10am and 1pm GMT and there are from 0-3 others logged in. I don't have this issue SP nor one the one other server I play on sometimes (it is also 1.7.2 vanilla). Anyone else have this issue? Is it common? Any suggestions as to what to try? My ping is good and I did a visual rout check and it also looks fine. Here is a short sample of what is happening.