Since I updated my iphone yesterday, I have disappearing app icons. More precisely, on each home screen page and in each folder there is one invisible app icon. The label is there and tapping the blank space above the label launches the app, but there is no icon. Leave a page or folder and return and it will be a different app, in a different position, whose icon is invisible. Has anybody else seen this?
In my case, the problem is specific to my 3GS, while my ipad updated fine.
I had the same issue on my iPhone 4 (but not on my iPad, iPad 2 or iPod Touch). I resolved it by resetting the iPhone. To do so, press and hold the Sleep/Wake button and the Home button at the same time for at least 10 seconds, until the Apple logo appears while restarting the iPhone? It will flash once after displaying the Apple logo, go black and then redisplay the logo as it starts up. The invisible icons are visible again.