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?

   

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(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’?