Cant get rid of the noise all over my texture (when using baked light)

Hi -

im using the baked lighting environment filter, and no matter what ive tried cant seem to get rid of this grainy patterning all over the model :(.

I thought it was to do with AO samples, but ive upped those to the max, along with samples for all other maps but nothing seems to have made a difference.

is there something i might be missing perhaps?

thanks for your help!