Bug Report time
The Height gauge under move is always one unit off unless you move the item horizontally, not sure if X & Z are also off as they are harder to check.
Decided to actually build the frames to carry on building, only I get "invalid location" every time I do, the frame is on the ground with it's height matching my ground height.
EDIT
It's not just the frames that wont build, anything "attached" to the ground gives an "invalid location" when you try to build it.