I have a number of HTML documents that render through the use of an external CSS file. All use a small animated background graphic image.

What puzzles me is the fact that the rendering, which is correct, is excruciatingly slow from my main machine (Debian Etch) when scrolling up or down the files or scrolling up or down the same files uploaded on an Internet server but works fine and fast when viewing the exact same files uploaded on the Internet server from another machine (Debian Sarge) on my LAN.

When I disable (comment out) the link to the CSS file then these HTML files on my main machine render much faster. All (HTML & CSS) have been checked through W3C validators and found to be valid code.

I even get messages that the window is not responding although it does after issuing the message.

The cursor is steady as a rock before loading any of these files in the browser but flickers a lot after loading even very short files, giving the impression that the cpu is very busy doing something else.

The CPU on my machine is AMD 2000 or something like it, supposed to be 1.6GHz. The browser is Iceweasel under Debian Etch.

I have no idea what sort of problem to look for, can anyone make suggestions?

Thank you for your help.

I found the problem was the rendering of the animated image which took over 99% of cpu time on a 19' LCD monitor and 30% to 50% of cpu time on a 15" CRT monitor with a Sempron 2000 and a Sempron 2400 (I do not know which machine has which CPU).

The animated graphic was created 5 or 6 years ago and its use of CPU time under Windows95 was never noticed.

Hope this helps someone.