Basically, it boils down to this … Chrome renders PNG’s exactly as one would expect it too, the same way that Safari and Firefox handle them … transparencies are … you got it, transparent!
Do you remember the ugly IE PNG bug where it doesn’t know how to handle the transparency layer and treats the alpha pixels ‘oddly’, almost randomly picking a color of choice and replacing your alpha pixel with a 100% opaque color? Well, looks like Chrome has a similar bug, at least … visually.
When jQuery Growl appends a new notification element to the DOM, and then fades it in … Chrome goofs the rendering up and makes the transparent pixels … non-transparent. It appears to only do this on pixels that are not 100% transparent (opacity = 0). See the screenshot below for an example:
As you can see, the corners are 100% transparent … but everything else is not … since the background image has a weird glow/drop shadow effect on it … and you can see the notifications above it that have there CSS opacity set to 100, the PNG renders perfectly.
This bug appears to be present when the DOM Element’s opacity is set to anything other then 100, such as a jQuery fadeIn or fadeOut animation that is executing.
Hopefully, they fix this bug in the next beta …