Hi Overnight my hash rate has dropped from 110Mhs to 92Mhs.
I've tested two pools with the same result.
I've tested other coins and their hash rate is reporting what I have mined before so it is not a rig issue.
Difficulty changes don't affect my hash rate.
Has there been a network change with this coin?
We have not had any network change. Check that your GPU's are not getting too hot.