Apple is reportedly working behind the scenes to address scratching and cracking of the iPhone’s glass back panel by certain third-party cases.

But there's another issue brewing behind the scenes that's sent Apple's iPhone engineering team back into the bunker for preemptive damage control. If you've been into an Apple Store (or visited Apple's site) recently, you might have caught a hint while browsing iPhone 4 cases (or lack thereof). Although Apple has just this week reestablished a wide variety of cases for sale, as of only a couple of days ago the only iPhone 4 case Apple even so much as mentioned on its site was its own first-party Bumper -- and still conspicuously absent from its lineup are slide-on cases. As it turns out, was by no means a cynical ploy to maximize profits.

We're not sure how seriously to take claims that some third-party iPhone 4 cases can cause the handset's rear glass panel to shatter.

To be fair, no one appears to have suggested that this has actually happened. But it is alleged by Gdgt.com that Apple engineers are busy investigating this potential problem, implying that the company is sufficiently worried that broken phones - and, by extension, a broken reputation - are a possibility.