Haven't long started this one. I can see where one Mohammed might be, I assume the other is on the left hand side of the grid beginning with the M given? Can't see any significance yet. We are not asked to do anything about it (like highlighting or anything). While I'm on here, what is 28 across?
Nothing to do with 2009. As you say, Mohammed appears twice. Just think of a phrase about Mohammed. Two related words appear in the grid, both 8 letters, one spelt forwards, one spelt backwards. All these words are just there, we do not have to do anything about them. Even if you don't find these words, it doesn't matter as you can solve all the clues from the clues given.