Build Identifier: http://hg.mozilla.org/mozilla-central/rev/a680fd777c3b Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/18.0 Firefox/18.0 ID:20120930030610 I notice the problem when I test Bug 795837 Steps to reproduce: 1. Disable HWA and restart 2. Open the http://jsecs.org/ 3. Zoomout(Ctrl+-) twice in my case 4. Mouse hover Back/Forward Button Actual results: Toolbar Items disappear. Good: http://hg.mozilla.org/mozilla-central/rev/f7c89de3ab43 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/18.0 Firefox/18.0 ID:20120915201302 Bad: http://hg.mozilla.org/mozilla-central/rev/b3f462d96fb5 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/18.0 Firefox/18.0 ID:20120916161603 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=f7c89de3ab43&tochange=b3f462d96fb5 Regression window(m-i) Good: http://hg.mozilla.org/integration/mozilla-inbound/rev/33087122ace7 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/18.0 Firefox/18.0 ID:20120916022601 Bad: http://hg.mozilla.org/integration/mozilla-inbound/rev/6ee831a85d12 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:18.0) Gecko/18.0 Firefox/18.0 ID:20120916033402 Pushlog: http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=33087122ace7&tochange=6ee831a85d12 Supected: Bug 788044

In adittion to STR in comment #0 3-1. Scroll down if necessary.

STR 1. Disable HWA and restart 2. Open the reduced html 3. Zoomout(Ctrl+-) three times in my case 4. Mouse hover Back/Forward Button

Umm, I can repro in Aurora17.0a2. STR 1. Disable HWA and restart 2. Open the reduced html 3. Zoomout(Ctrl+-) several times till text "AAAAA..." disappears 4. Mouse hover Back/Forward Button Regression window(m-c) Good: http://hg.mozilla.org/mozilla-central/rev/88ba578cbaab Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120816111151 Bad: http://hg.mozilla.org/mozilla-central/rev/a79132ac2f05 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120816175051 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=88ba578cbaab&tochange=a79132ac2f05 Regression window(m-i) Good: http://hg.mozilla.org/integration/mozilla-inbound/rev/a6c9088eb267 Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120816034000 Bad: http://hg.mozilla.org/integration/mozilla-inbound/rev/276b57e03eba Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 ID:20120816040500 Pushlog: http://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=a6c9088eb267&tochange=276b57e03eba Suspected: Bug 779399

Assigning to roc but leaving in nominate.

Duplicate of bug 787947 probably

(In reply to Robert O'Callahan (:roc) (Mozilla Corporation) from comment #5) > Duplicate of bug 787947 probably QA - can you verify?

Could reproduce with a build before the implementation of bug 787947 and couldn't after bug 787947 landed on central. (used STR in comment 0). Checked on XP with Aurora and Nightly. Looks fixed both on Aurora and Nightly.