User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1 Build Identifier: 2.0.0.16 (20080708) When composing mail with non-English characters (Japanese specifically - no other languages attempted), T-Bird pops-up warning dialog "The message you composed contains characters not found in the selected character encoding...and illegible by the recipient" with options "send in UTF-8", "send anyway", and "cancel". This is the message that does and should pop-up when the mail is sent, but it pops up spuriously every ~5 minutes, probably during an auto-save. Reproducible: Always Steps to Reproduce: 1.switch input to Japanese. 2.type anything. 3.wait a few minutes. Actual Results: T-Bird pops-up warning dialog "The message you composed contains characters not found in the selected character encoding...and illegible by the recipient" with options "send in UTF-8", "send anyway", and "cancel". Expected Results: nothing I've had this happen on a windows XP box, and the two latest Mac OS X versions.