Comment 173 for bug 125970

Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9pre) Gecko/2008041306 Minefield/3.0pre
But it's been like this on at least the few last builds.
I'm using Vista SP1, Core 2 Duo T7500 2.2, 2gig of ram, 8400gt.

I just added a new attachments which demonstrates the slow down.

The html file contains very large tables but speed is very good if there isn't a fixed div, so I don't think this is related to bug #54542.

With only one (unlike comment #105) fixed div in the page 2008041306 Minefield/3.0pre is really slow, whereas Firefox 2 doesn't have any trouble displaying this page, not slow down at all compared to minefield. Safari and Opera are faster than Firefox 2 on this page as expected.
Even if there is a lot of code, Minefield stops using resources as soon as the position of this div is changed. It's h2#dateTitle{ on line 424 in the css file.
Firefox 2 is a bit slower if that div has a fixed position but it's nothing compared to the slow down occurring in minefield.

I first thought it was the transparent png used as background but removing it didn't change anything (bug #105).

As Rowan said in comment #111, there is a big improvement when the window is resized to a smaller size, but with a lower height, about 500px, but that's probably normal as it's a lot smaller window and faster to generate.

I don;;t have any problem in gmail, as other poeple talk about it early but that's probably not related. Probably Bug #424915.
I don't know about minefield on mac, I'll have a look tomorrow.