I'm seeing strange behaviour with accented characters in MT 4.1.

If I publish a post with an accented character, eg 'ö', the individual entry page will display it correctly but the main index will display it as '�'. Both pages are set as UTF-8, as shown in the 'meta' tag and in Firefox's 'View > Character Encoding'.

If I then manually 'Save & Publish' the main index template, the character displays properly on both pages. However, this only lasts until the individual entry is edited and the main index is rebuilt automatically, at which point the main index page becomes broken again.

Can you post a link please?

Here's an example post. At the moment it's actually the reverse of what I described above: it's broken in the individual post but fine in the main index.

The validator refuses to even check that page because of an invalid character. I'm not sure whether that's the same character as you're seeing displayed improperly, because that error actually corresponds to a blank line, as far as I can see. It's possible you pasted something in you shouldn't have.
Try deleting anything between the bit of template that outputs the entry title and body to check if there's a screwy invisible character in there.

Yes, that's the character I'm talking about. It's not a valid Unicode character so the validator breaks, but on the main index page it's fine.