(I'm using RH8 v 18.104.22.168 under XP SP3, all latest Windows updates. Building to a WebHelp output.)
I have many topics in which the images have a Fade In effect (Dynamic HTML Effect > Page has been loaded > Fade in). I build it into WebHelp.
This works beautifully in IE8, but in Google Chrome, and Firefox, there is no fade in (I can live with that I suppose) BUT some images are there, some are not - just white space where the image should be. I get identical problems, topic-for-topic, in Firefox and Chrome. Some fade-in images display, some don't. They are a mix of JPG and GIFs.