That has happened to me many times but only after I sync my iOS devices which is once a month. I've previously deleted the app but after the sync I see that it has been reinstalled. I just delete the app again and that always fixes it. I don't know why it happens, it just does.
Pete
If you click on one of the "Remove" buttons, it will change to "Will Remove".
And if you tick off the "Automatically install new apps" box, then anything downloaded to iTunes will be downloaded to the device as well.