If Google is intentionally filtering suggestions that would offend Muslims they're doing a miserably bad job. Try "Is Islam"
("violent" / "evil"), "Muhammad is"
("a false prophet" / "satan" / "the antichrist") or "Islam should", "Islam will", etc...
If they did intentionally remove that result I bet it's due to a particularly nasty suggestion that made it into the list somehow -- which is totally possible if you all remember how Bush critics managed to link "miserable failure" to the official Whitehouse biography of President Bush. There could plausibly be a new sort of "
Google bomb" that gets things into that suggestion box. Heck, for that matter, this could be an action by Google to rectify a semi-malicious tamper by pro-Islam folks -- it's totally possible that somehow something like "Islam is the only true religion" got pinned to all 10 suggestion slots (that'd be the "bug") and they just disabled it while they're fixing it.
All totally conjecture, I know, but my point is that there are a number of reasons ranging from censorship to error to something in the middle.
edit: "Quran is / The Quran is" has pretty colorful results too.