The thing I don't understand about cortosis woven weapons is that in the EU books cortosis shorts out a lightsaber. This never happens in the game, and eventually the lightsaber can cut through the cortosis.
I think Spectre of the Past and I, Jedi made mention of this.
He means the number on your stats.
Example: Do you leave strength at 15 hoping a str modifying item will boost it to 16 thus getting the extra str bonus.
+1 bonuses only occur on even numbers.