This is not expected.

https://bugzilla.mozilla.org/show_bug.cgi?id=679650

I opened a bug so you can track the issue and provide more information to the developers.

Actually, if you could try the following possible fixes:

• Turn on smooth scrolling (Firefox > Options > Advanced > General)
• Restart your computer (it could just be laggy from having too many things open at once)
• Start in Diagnose Firefox issues using Troubleshoot Mode see if the problem is still there, if not, disable extensions one by one.
• Update your mouse drivers/settings
• Update your graphics drivers
• Check for malware

And let us know if any of these helped.

I tried these, but I think it is more something to do with the text size on the page. The mouse now moves a certain amount of lines per wheel movement. The larger the text size, the further the scroll moves. It only does this with firefox and I have smooth and auto scrolling on. I'll recheck my graphics drivers because I was having a problem with them last month, but I don't think it's related...

Is it still happening? Can you provide some example pages where this occurs? What kind of mouse is it? Do you use Set Point or Intellitype software?

Please post back here or in the bug

yes, it is still happening, though I've gotten better at ignoring it.

my touchpad, i think, is an elan ps/2 port smartpad and my mouse is a microsoft basic optical mouse v2, both componants are working correctly and have the latest driver update installed.

The difference between img 1 and 2 is one scroll wheel turn down. In image 3 I have decreased the view using control - (minus) and in image 4 I have scrolled down one turn of the wheel. you can see that instead of a full page turn, like between img1 and 2, it only moves about 2/3's of the screen down. As every tab seems to have a different text size, the amount of scroll turn changes between tabs, sometimes varying as much as several pages each scroll turn.

One thing I have noticed, is that the vertical scrolling speed on my mouse settings changes the amount the pages moves when turning the wheel. This only seems to change when in firefox. changing this while using word has no effect on the page movement in word. Increasing the vertical scrolling speed will make the scroll turn move further.

I have adjusted the scroll settings in options, and no adjustment of settings, (autoscrolling on/off, smooth scrolling on/off in and combinations of off/on) has made this error stop occurring. I have checked for malware etc, no issues. This happened from the instant I upgraded to FF6, so I think there is a corrolation there.

If you could nail down a regression window (rather than saying it happened between 5 and 6) we will have a much better chance of getting attention to the issue. Instructions/software at http://harthur.github.com/mozregression/

What I think might be happening is that it is turning a certain amount of lines per page, and if the line size is larger, it moves a larger distance instead of moving visually one page, ie, if you can see 10 lines of text on the screen when the scroll is adjusted to one turn turn, then if you adjust the text so that you see only 5 lines, when you turn the mouse it will still move 10 lines, therefore 2 pages. each site has it's own text size so each site, each tab, moves at a different amount. Since I read online constantly, it can be very annoying. mostly I adjust the text size untill it matches the scroll adjustment, but that doesn't always work.

the space down and page down button still work exactly right.

I have done the regression, and I'm not sure if the answers indicate anything, or if I've changed my mouse setting and have skewed the results. from what I can tell, in the middle of may the problem became as it is today. on may 02 the problem only occurred if the text size was increased over a cetain amount. if the text size was small enough, the problem didn't occur, but when you increased to what I would call medium large size text, the scroll started to move based on text size.

Later tonight, when I have more time, I will keep going back with this. I hope this helps (and isn't totally crazy making useless info!)

sorry, it was the opposite. the smaller the text, the wonkier it got. larger text worked fine. now at march 01. of the 14 text sizes the page let me have, the largest 6 text sizes worked exactly as it should. the smaller 8 were wonky. wtf?

I have now regressed to 15/1/11. same error. is this even possible? I don't know enough about this to know whether I am looking at an error I have made myself. I think I'll stop until somecan can help clarify this for me. Thanks for all help!