Martin, thanks for your reply. Not sure - why does it make a difference if there is a viewer or not? IMHO it's useful to be able to view multiple instances of a file no matter which program you use for viewing. And again - I'm fairly certain this was possible two or three years ago, which is why I'm not sure if the "new" behavior is an intended feature or not.
I understand that it is useful to have one file opened in more viewers (immutable). But it is wrong to allow to have one file opened in more editors (mutable).
Yes, I mean that when clicking back, you are not scrolled to the top, but to the directory you came from. Since it's rather unlikely that you'll want to click on the directory you just came from, being automatically scrolled to the top of the directory would seem more natural to me.
It is common behaviour in commander-style file managers. I find it useful. E.g. if you want to peek into directory before deleting or transferring it. Or if you want to peek into multiple directories, one after another.