Not all indents are 'normal'.

Our Somnus Chatsworth [cost £1500 ] was replaced by Somnus on 31st October 2014 because the fault was in the internal springs.

They were collapsing.

The replacement showed same problems developing after only 3 months and after 4 months we contacted the company again.

Their inspection on 9th April showed that the same fault had occurred so we are now waiting for yet another replacement.

There would seem to be a major problem with the springs, perhaps lower grade steel or just sloppy manufacture.