Invisible blocks in the world

When ever I enter into a world i get a visually blank world. the blocks are still there and it is not a world generation issue, they are just invisible! Weather it is online, lan, or single player no blocks load except the clouds and the sun/moon. i can see particle effects(ex, walking, bubbling lava, digging dirt) and changes in light. i can also break/place blocks as normal. i can see the inventory and whatever i am holding in my hand, but once placed they disappear, i can however pick them off of the ground and they do re-appear visually in my inventory.
*Note 1- my minecraft is fresh installed and has not been modified in any way.
*Note 2- i have a rather unique setup on windows 7 where my users folder including app data folder is on a different hard drive than my boot drive may this be the issue?