I see you got no answers to your question! I wonder if you managed to sort it out?
I am currently having similar problems. Using CS3, I have created an informational tool for our client which pulls all the text-based data from XML files. I am using a dynamically created instance of a TextField which I populate from the XML.
The problem I'm having is with 'letter spacing' between bold words and non-bold words within the lines of displayed text. Basically, the spacing is variable. There seems to be no rhyme or reason to it. The problem is exacerbated by the fact that the project has to scale to be able fit several different screen resolutions; so on one machine the bold word will be overlapping the preceding word by about, say, two pixels, with a corresponding increase in the gap to the next word, whilst further down the same sentence the opposite will be true for another word.
I am using embedded fonts. I have both versions (regular and bold). To the best of my knowledge these are embedded and instantiated correctly - indeed, apart from the above problem, I am having no other font issues - everything is working as it should.
Whilst I'm sure that I haven't tried 'everything' to fix it, it feels like I have tried everything - every combination of kerning, letterspacing, antialiasing, different fonts, font sizes, special tags in my XML, standard tags in my XML, no tags in my XML, not using XML, formatting using HTML/CSS, formatting using setTextFormat(TextFormat Object, x, y), downloading the Trial of CS4 recompiling for Flash Player 10 (still the same)...
Everything I try results in more-or-less the same outcome: bold words and phrases will always appear 'somewhere' near to where they're supposed to be, but don't for a minute thing that they'll stay there.
I've run out of ideas.
Is this a known bug? Does anyone have any ideas? Can anybody help me?
I see the first bug report here is from 2007, and the second is from 2009. Here I am in 2013, Flash CS6, publishing for version 10.3.
I have the same exact problem. It shows up sometime when an Italic word follows a regular word:
Once in a while, some of my italic words will be shifted to the left, and overlap the last character of my regular words. Yes, they are embeded as well, (text read in from xml) and sometimes just changing what line the words fall on in the paragraph will help it. But of course, I don't want to adjust my paragraphs and sentences just to accomodate this visual bug.
No solution, just stopping by to say I am too now having this bug, 6 years after the first poster. Ohh, flash font embedding.