I agree with quest_for_silence, it is not normal in just six months. The elastics get loose, they have in my case, but it was like after two years. But as MikeC says, it's really easy to replace them. I did the same as he said, went to a sewing shop and bought the ones I thought would fit best. And ...

Indeed a great option for mATX cases, and having the PSU at the bottom is something I like. The only thing I don't like much is the Depth, on their website it says that it is 490mm which is 20mm deeper than my SOLO (470mm), for me a bit too mcuh.