Mozilla/5.0 (Windows NT 5.1; rv:2.0b5pre) Gecko/20100828 Firefox/4.0b5pre http://hg.mozilla.org/mozilla-central/rev/6e3f6d18c124 STR: - goto http://www.janbambas.cz/mozilla/bugs/crash-nsWeakFrame/app.php - click on the "Click to add new" text and leave the mouse at its position - right after a yellow rounded bar shows right bellow the mouse cursor go with the mouse down underneath it until "Click to add new" text shows - you should crash at this moment, if not, go with mouse up again - timing is important, so you might not succeed to reproduce on the first try Sorry not to have a more minimal test case for this, I'll work on it if needed.

Reports: http://crash-stats.mozilla.com/report/index/bp-6790a912-ef5c-40e4-9d1f-7b5762100828 http://crash-stats.mozilla.com/report/index/bp-e3357ea0-505f-4e4f-9c7a-892e62100828 http://crash-stats.mozilla.com/report/index/bp-d5d5f1e5-0834-41c2-8b97-74f592100828