Drawbacks using javascript to fix the PNG issue:
- higher chances theat the IE-6 visitor doesn’t have javascript turned on, than on a modern browser
- ~1-2 sec. flicker until page finishes loading and javascript completes processing (on IE-6 js is slow)
- fixing repeating transparent background images is very buggy in these type of scripts, in most cases you’ll get a CSS mess…
So I don’t recommend any PNG “fix” script. Instead create 8 bit PNG images with alpha transparency:
http://www.ethanandjamie.com/blog/37-user-interface/81-png8-transparency-without-fireworks
You’ll need to follow that tutorial because Photoshop can’t save in this type of format. Then simply use them for IE 6 in a dedicated stylesheet.
The only drawback here is the lower quality of 8 bit (256 color) PNG images converted from a image with a high number of colors (which should really be rare on a website because of their size). But that shouldn’t be a problem because IE 6 users are used to sh* quality anyway 🙂