I'm using an 0.47 nightly from 06 Sep on Ubuntu Jaunty Linux. I've been using Inkscape (0.46) for about 8 months now for a variety of random web graphics. I'm not an art professional by any means.
Anyway: in the nightly, while it's fixed some chronic crashes from 0.46, has itself a couple of quirks. One that is particularly annoying is this: I select some objects/paths, and then do something - maybe set clipping, or group, or change color; it's not completely consistent or at least it seems that way. After an operation like that, my stuff apparently remains selected (according to the UI), but subsequent attempts to use the arrow keys to move the elements around have no effect. I have to de-select and reselect the elements and then of course the arrow keys move them around just fine.
I'm wondering if this may have something to do with layers, or something else about the application with which I'm not very familiar. One reliable way to make the effect happen is this: draw a rectangle, type "s" to switch to the "select" tool, and then go to the "fill & stroke* box and set "blur" to something bigger than zero. After that, the rectangle will be blurry and apparently selected, but the arrow keys won't do anything (for me anyway).