LyX ⇒ \columnsep offset both column and heading offset

[amitrotem]

hello

i have an issue with 2 column documents,
it seems that \columnsep add space to the right of both column.

so when i change between one & two column i always have to redefine the geometry with \newgeometry{...}

this also affect heading and footers offset, they are not centered.

i use LyX 2.0.7 on win8.
i've added an example lyx file and the pdf i created from it.

is it possible to change from one to two column without redefining the geometry?

thanks in advance.