User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; it; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7 (.NET CLR 3.5.30729) Build Identifier: http://img13.imageshack.us/img13/7163/97406189.png http://img13.imageshack.us/img13/6435/42449136.png Reproducible: Always Steps to Reproduce: Sende an email from yahoo mail(from yahoo.com) to thunderbird.

Resolved adding .headerValue{ word-wrap: break-word !important; } this to userchrome.css

Please don't resolve anything as FIXED unless a code change was checked in. This looks like an extension issue (MailTagger?). What happens if you disable that extension in Tools > Add-ons? Also, see the discussion in bug 520249 and bug 530047.

Sorry, I meant the Display Mail User Agent extension, displaying the 'Y' for Yahoo, https://addons.mozilla.org/en-US/thunderbird/addon/562

Hello, sorry for marking this bug as FIXED. I have tried to disable the "Display Mail User Agent" extension but the problem persist.

No problem, your workaround in comment #1 may give a clue what's happening, and it may be related to one of the other bugs I've mentioned in comment #2. From the screenshots it appears that you use View > Headers > All, does this also happen with the "Normal" setting? And, do you notice this issue with specific messages only or across the board?

Yes, i use View > Headers > All. I have tried with "Normal" headers and i see the buttons! This happens only with some e-mail.

Thanks for getting back. Ben has resolved it as a duplicate of another bug for which a fix was checked in that becomes effective with the TB 3.0.1 release. Coincidentally 3.0.1 is likely to be released today, thus please double-check after updating if your issue is resolved also in the "All" header mode.

Installed tb 3.0.1 and now the buttons does not disappear :) I have tried with both normal and all header. Thank you!

verified per reporter.