583058 - Scrolling sometimes ruins youtube.com visual view

Status: RESOLVED DUPLICATE of bug 579736

(Core :: Layout, defect)

Description

[Ognyan Kulev]

User-Agent:       Mozilla/5.0 (X11; Linux x86_64; rv:2.0b2) Gecko/20100720 Firefox/4.0b2
Build Identifier: Mozilla/5.0 (X11; Linux x86_64; rv:2.0b2) Gecko/20100720 Firefox/4.0b2

Since I upgraded to Firefox 4 Beta 2, when viewing YouTube videos and do window scrolling using the mouse, the content is not scrolled properly. It looks like window content is not repainted properly. Visually it's like a few horizontal lines are taken and repeated in the whole window content - some scrolling problem. The flash rectangle with the video is the only thing that looks OK. When trying to "Print Screen", everything is fixed before taking screenshot, so no attachment is attached.

Reproducible: Sometimes

Steps to Reproduce:
1. go to youtube video
2. scroll window

Actual Results:  
repeating multiple lines

Expected Results:  
correct display

flash part is OK. Print Screen key fixes display.

Comment 1

[Ognyan Kulev]

Attachment: Video demonstration

Using a cheap Nokia, I tried to catch demonstration of the problem. Unfortunately, the resolution is awfully low. What becomes clear is that the problem happens only when scrolling to top, not to bottom. Not always reproducible.

Comment 2

[Ognyan Kulev]

Attachment: Photo of ruined display of page

This photo demonstrates that few horizontal lines are taken and all of the display is filled with them. The number of lines and the lines themselves change in each scrolling movement upwards.

Comment 3

[Ognyan Kulev]

It's worth noting that I updated from Beta 1 and I don't remember such problem in Beta 1, so it should be something with the retained layers.