Imagine that app icons on your iPhone’s Home screen decided to play a game of masquerade. You tap an app displaying the Bento icon but the MacGourmet app opens instead. The displayed text names of the apps remain correct, but the icons are wrong.
Numerous iPhone users don’t need to imagine this. It is exactly what happened to them. According to reports, it is especially likely to occur immediately after updating to iPhone OS 3.0. In a few cases, the symptom is even more disconcerting: rather than swapped icons, the items are the equivalent of “white noise” (as depicted here, a graphic I grabbed from an Apple Discussions thread).
Simply turning off the iPhone and rebooting has no effect. According to most reports, even deleting all the apps from your iPhone and adding them back again will not prevent the symptom from recurring. Restoring from a backup is not likely to work either. At least this appears to be the consensus.
What seemed to have the best shot for a fix (short of a full restore of your iPhone) was to tap Settings -> General -> Reset and select to “Erase All Content and Settings.” After that, you have to re-enter all your settings and resync all your content.
Most of the people reporting the problem were running Windows. However, several Mac OS X users reported the symptom as well.
Admittedly, users are shooting in the dark a bit here. No one knows for sure what the cause or solution is. It would really help if Apple officially acknowledged this symptom and offered a definite fix via one of its Knowledge Base articles.