Misaligned sidebar

I've noticed this on a couple of occasions.
The sidebar is misaligned vs the main area.
https://oc.skjoldebrand.eu/index.php/s/22kck6QjlOCLsJf

Is there an easy fix?
(Hopefully this will be the last thread from me for a while )

Could you please post an url to your site?

http://martinskjoldebrand.net/
I based it on database and settings from a properly behaving site, but ...

Now, after resaving a module in the sidebar - it aligns properly ...

Thought I - it still misalignes after adding articles that end up in the right sidebar ...

I eventually noticed that the address with www. didn't misalign the sidebar, while the address without did.
So I implemented a backend workaround that redirects martinskjoldebrand.net to www.martinskjoldebrand.net. As to why on the other hand, I still don't know.

Right now I can't check what might be wrong, but perhaps one of the modules has some html errors (tags that are not closed, or to many closing tags)?

I thought something the like, so I disabled one of them but it didn't help. Nothing else is in the sidebar. Also, wouldn't that affect both the www-adress and the sans-www-address?

Very strange... I would search around differences between www and no www, maybe some files are not loaded properly? Maybe when you have domain without www and css/js files are loaded from a domain with www crossdomain issue comes to play?