Comment 7 for bug 63098

Relevant part of the answer from the upstream developer:

"Yep, we've had the bug reported a few times as well. The README describes the correct format, but I completely agree that it could be made easier. And since I had some free time, it's fixed. :) Unfortunately, you'll have to either get the CVS version, or wait until the next release is made to get the newer parser.

Now the keybinding parser will accept the values:
" None+F1 " (extra spaces are ok)
"F1" (ommitting "None+" is ok)
"Control+Win+F3" (more than one special key)
"F3+Win" (order doesn't matter)
"`" (can use the key instead of "grave")
"`+Win+F3" (will use "Win+F3", it takes the last valid key)

As well as any combination of the above, like:
" `+Win " (extra spaces, out of order, and "grave")"