We have converted all tiny files to UTF8 and this is why we are getting this error in Firefox since the meta tag in the tinyMCE html files specify iso-8859-1. The problem only occurs in Firefox and it seems that Firefox uses the actual content encoding specified in the meta tag while ie just checks the actual file encoding. We consider Firefox to be correct in this case and will address this before the release.
EPiServer Development Team
I noticed the classic "ï»¿" garbace from UTF-8 BOM characters not handled correctly in the TinyMCE editor using FireFox browser.
Is this a packaging error? Or is the ASP.NET settings affecting TinyMCE? Or is it a native TinyMCE defect?