506924 - FF 3.5.1 slow to scroll the page with lateral scroll bar

Status: RESOLVED DUPLICATE of bug 477564

(Firefox :: General, defect)

Description

[enrico.amisano]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; it; rv:1.9.1.1) Gecko/20090715 Firefox/3.5.1
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; it; rv:1.9.1.1) Gecko/20090715 Firefox/3.5.1

Hi to all
I have installed FF 3.5.1 and in my Intranet applications I have a strange behavior, a lot different from 3.0 version.
After the page has been loaded in the browser (I wait for some seconds until the page is full loaded), when I try to scroll with the lateral bar, FF hang up in a random point of the page (not the same point of all my tests).
I note that the Pc CPU in that moment is 50-60%.
After waiting 2-3 seconds, the scroll bar is again available and I can proceed with scroll bar at the end of the page.

I note this behavior in 4-5 pc of my company.
In one of these PC, I have:
- tried to reproduce the problem with 3.0 installed --> no slow problems 
- update to 3.5.1 version: the problem appear as in my PC

Initially I suspected that was a problem for a long, long page but anyway the problem doesn't appear on 3.0 version and after some tests, it appears also in short pages.
For my users this is a nasty problem because they have to try to scroll and don't have the possibility in that moment.

I have tried to:
- start in safety mode --> nothing to do
- start with a new empty profile --> nothing

I have opened a discussion on Mozilla Europe but also there isn't nothing to do: some users have my problem, any other NO.
http://forum.mozillaitalia.org/index.php?topic=40206.15

The problem appear also off-line in the same Html page but dowloaded to the PC.
You can try it to reproduce the problem.
You can enter on:
ftp://80.16.163.19
utente: testff
pwd: testff

There is a zip with the document inside.
Many thanks in advance.
Enrico-Italy

 




Reproducible: Always

Steps to Reproduce:
1.Open the page
2.scroll the page with the lateral bar
3.the browser hang up 
4. if the problem don't issue, try to scroll many times


Expected Results:  
Run as in 3.0 FF version.

Comment 1

[Ria Klaassen (not reading all bugmail)]

Does the page contain a form with a lot of check boxes? In that case retest with the preference browser.sessionstore.privacy_level to 2.
How to change the value of this pref see http://kb.mozillazine.org/About:config

Comment 2

[enrico.amisano]

None checkbox in the form.
Many input type text fields and many and many input type button.
If you want, you can test directly online the problem at:
http://gialloporpora.github.com/FFslow.html

Comment 3

[Ria Klaassen (not reading all bugmail)]

I see indeed some (vague) performance decrease between Firefox 3 and 3.5, but that seems to disappear with browser.sessionstore.privacy_level to 2.
Can you retest? Then you can resolve this bug as a duplicate of Bug 477564.

Comment 4

[enrico.amisano]

Ria, browser.sessionstore.privacy_level to 2, FF seems to be much more faster.
Now I will test on the users PC's where the application is used every minute and I confirm you the solution.
Many thanks, you are fantastic !
Enrico

Comment 5

[enrico.amisano]

After many and many tests the problem is really solved with browser.sessionstore.privacy_level=2
Many thanks.
Enrico

Comment 6

[Ria Klaassen (not reading all bugmail)]

Great, thanks for testing and reporting back, Enrico. Then it can be duped to bug 477564.