at the moment ReReplacer sees the html. But hard to tell from just this info.
Can you give me (super) admin and (s)ftp access so I can take a look?
And tell me on what url I can see/reproduce the issue.
You can use the 'Confidential information' button in the forum editor to hide sensitive information.
I am not sure how your website works and how the content is generated/built up.
But the moment ReReplacer gets to see the html, the whole header section is not there yet.
I guess this is a nicepage thing.
If so, then ReReplacer (and pretty much any other plugin) is unable to affect any html in that area.