I'm very used to use edge bindings in my workflow, but since I've updated to 12.04 Unity forget my edge bindings settings on every new session.
Why it is appening and how to fix it?
I think that the real problem is not that "Unity dosn't remeber the bindings" but rather that something is blocking the edge pixels from being reached. If you do anything that forces compiz to refresh the settings (enable or disable widget layer for example), the edges are working again. I think it's like that compiz is running but it is behind unity not on top (like an inactiv window i supose).
This explains the working solution for startup programs, because its runs again compiz and forces that refresh.
I haven't thought so, i all i did to fix the problem was a restart with alt+f2 and runing compiz --replace command as soon as the desktop started.
In conclusion, something is blocking compiz edges, and stays on top, till you resfresh it in anyway.
I like to believe it will be fixed, cause the edges is THE most amazing thing for ubuntu in general.
