User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; ja-JP-mac; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14 Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; ja-JP-mac; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14 https://www.e-tax.nta.go.jp/download/ source has <div class="clear"><img src="http://www.e-tax.nta.go.jp/img/spacer.gif" width="600" height="1" alt="" /></div> . It's mixed state(https,http). Not warn on Mac OS{, but warn on Windows.. same config}. Reproducible: Always Steps to Reproduce: 1. 2. 3. Actual Results: Not warn mixed state (https://www.e-tax.nta.go.jp/download/)

I'm seeing this bug with Firefox 3.0 RC1 on Windows and 2.0.0.14 on Mac, both on the submitter's URL and my own site here: https://dietrich.cx/wiki/Development/CookieWhitelistWithButtons Since both pages are IMHO "encrypted with some unencrypted information", the check is broken, or the preference description is very misleading.

For a long time, mozilla's core code for determining mixed mode has had a blind spot for images. What you describe here is a duplicate of bug 135007. Despite being a very old bug, it has recently gotten lots of attention and new patches, so we hope to have that fixed soon.