I am working on using some existing PDF in an Illustrator project. This generally works well, as they were created on my computer originally and thus have access to all the source fonts. However I've run into a bug/problem which I can't seem to work around. Despite having the correct fonts installed, it sometimes uses Myriad Pro as a generic replacement. Generally, I simply change the font for that text area and continue working.
The problem is that in a couple cases, the text area contains an unusual character which appears in Myriad as simply a boxed X (indicating it as invalid character) - furthermore, when I try change the font for this text area or highlight the character to change it, the change simply doesn't hold. I can select an alternate font and no change will occur - the text are will still use Myriad Pro. (Oddly, if I highlight the character in question and try to select a glyph, even changing the font under the glyph selection window doesn't take.) If I delete this character I can then change fonts, however it seems like an error that simply having a character in text area would prevent if from changing to a font which contains the glyph. While I can manually retype this, such characters appear many times in many documents, so trying to figure out what the character was supposed to be a retyping it would be very labor intensive (esspecially as opposed to simply using the find option to replace all the occurences).
If it is of any use the original source font is Bitsream Vera Serif, an example failed character is a approx. equals sign (squigly equal) and if I delete the text and manually retype the character, it works - it simply won't change fonts while the unknown character in Myriad is there.