Glitch: Placing a Roof Slope with a Blue Light

When messing around with the newest "HD" version of the engine, I noticed a strange glitch. When trying to place the light blue light on the side of a block (you can see some in the following image), the game would place a shingle-roof slope instead of the light. This only occurs on 2 sides of a block, and only happens with this one type of light.


Image:

i got it too. Tell your computer specs please.


*EDIT* it's so sad because it's one of my favorite light colors in building

i would guess that some of the light blue block numbers are the same as some of the shingled roof block numbers.