Rather than try to explain it, I took 2 screen shots.
I frequent many forums and am very tech savvy, so I’d say it’s a problem with the site as it only happens here, and it’s random.
(it sometimes looks like this, sometimes its normal)
Today is the first time it’s been happening to me.
Yeah me to. This happens every once in a while. (And I am not on Windows nor Firefox so it is not a Firefox or Windows thing).
I think the issue is that the CSS file, which is a content description file, is getting messed up or lost on transfer to your browser or is randomly not being sent at all so that the code to tell it to look all fancy is lost so it gets rendered as plain html instead of the fancy stuff we are used to.
If I had to guess (and I run servers for webhosting)…
From comments I have read it sounds like M4C runs on a cluster of machines. Not just a single server. I would guess that the forum software install on one of the machines (or a subset of the machines) is missing one or more CSS files or similar setup files that define the theme. This is why doing a refresh sometimes “fixes” the problem momentarily. It depends on which server is hit that request.
This is similar to the time screwup a few weeks ago where sometimes the posts etc were off and out of order. One of the servers clocks was messed up.