I feel as though people are blowing this out of proportion. Who really looks at these cracks everyday and says wow this like stinks. My xr30 and xr15 have cracks. I loosened the screws slightly to reduce stress. Cracks are now barely noticable but do not mess with the function of the light. It's not like my cover is going to fall into my tank lol. Plus it's in a canopy so your not going to see them unless you turn the light off or are trying to look for cracks while staring at a bright light.