Hi. I have same problem, but no jailbreak, normal iPad2.
I have app Eesti Ekspress (Estonian magazine), it works fully, if I find it in Search, but icon is lost. In apps list (Settings) app is also listed. I can't Install it again , because it shows gray INSTALLED botton in Store.
Where I can find /regenerate icon?
And yes, I looked carefully every my page and subfolder, it's really lost!