I'm not sure if I changed this, but on my Xubuntu, C-A-d is "Show Desktop". Now, every other snaptile combination work, including rectangular areas that include d, but when d is alone the desktop shows instead of the current window being set to the d tile.
A workaround would be to bind "Show Desktop" to the Win key + d like a sane person, but I felt I should report this issue.
Side note: should I write C-A-d or C-M-d? Or both are ok by convention?
Thanks. Cool app.