Perhaps you have encountered this:

You create a text input field in Flash, you export it to an swf, test that swf directly on several machines, and everyone can type their email in fine using the @ and " keys on their keyboard. Then, you put that same swf in a html page only to find that some users now have to type their @ and " characters the wrong way around. We tried various character encodings and charsets ... no resolve yet.

If you know what is likely causing this and what the resolve is, then I would appreciate your feedback.