No fix that I'm aware of. The drivers for the ir blaster are in the touchwiz kernel or so I read once. CM uses a different kernel altogether, which doesn't include whatever is necessary for the ir blaster to work properly.
That is the price you pay for using a non touchwiz rom, you lose the touchwiz features that Samsung develop, the ir blaster is one of those features.
You may want to post your question on an official CM forum. Maybe they can help you more.