New line formating issue

There seems to be a problem with new lines. In the following image, the last 3 lines contain new lines, but in the preview and actual comment, the new lines don't appear.


Edited by Simon Anciaux on Reason: typo
I can't reproduce this on my own, at least not from your image. Is there an example post of yours somewhere on the network that demonstrates this?
The screenshot is from this post