How to get iOS to properly respect the "apple-touch-icon-precomposed" link attribute for a "web app"

I have created several web apps for iOS that employ the apple-touch-icon-precomposed link attribute method for custom home screen icons without the gloss. However, I have run into an issue recently, where, after adding the home screen bookmark and then running the app and exiting the app (via multitasking), gloss is applied to the icon! I don't understand why this happens. I can't reproduce it on an iPad 2, but this keeps happening on my i开发者_如何学编程Phone 3GS running 4.3.3. Also, it seems that it might have something to do with putting it in a folder?

The app is located at http://pattern86.com/apps/color if you'd like to inspect the code.

Basically this is what happens:

1. Add the app to the home screen. (No gloss--everything's good at this point.)

   

2. Quit the app from multitasking (It already shows the gloss here!)

   

3. Now the icon has the gloss effect! What gives?

   

(reposting as an answer, as requested:)

Could be something to do with the icon itself. Does the image have an alpha channel? Do your other, working, apps’?