Somes corrections

Tested agains eliot : http://www.nongnu.org/eliot
Still one little problem to resolve...
You're right that this is a bug, but this isn't the right solution to it, since it could allow a word to go off the end of the board. The right solution is to keep the code I had (with less-than) but move those two lines to the top of the loop, just before the `get_index()` call.