Skin modifier shrink/fatten (alt-S) strange behaviore

I hope I’m not alone here, but when I try to do the skin modifier in 2.75a, and decide to shrink or fatten a point, Blender instead moves the vertex along a slanted axis. I tried, wiping my settings and plugins with no luck. I’m doing this on Linux and made sure the window system uses the meta key instead of the alt key. My pivot point setting is normal too, so I’m not sure what to do.

its ctrl+A to adjust size of a point…(windows lol )

Hmm… my bad. Even explicitly clicking shrink/fatten was doing the same thing. Anyway, if it’s ctrl-A, what’s alt-S for?

See https://www.blender.org/manual/modeling/meshes/editing/deforming/shrink-fatten.html.
Ctrl+A is just applicable for the skin modifier