What is the point of the "Hide" button on Active?

[Glurgle]

There's a zombie thread that's popped up in Active, so I clicked on Hide and it disappeared. All good!

But every time I go back to Active, there it is again. So I'm not really sure what the point of "Hide" is? Or should it be more "permanent" and isn't working as it should?

Thanks!

So when I clicked back on Active, there it still was. But when I hit Refresh, it disappeared. I have noticed that happening sometimes, when I click on Active it's the same as it was before, until I refresh.