Users are reporting that some iPhone 4 handsets have a problem with the proximity sensor which is supposed to shut down the touch screen during voice calls.
The official Apple forum is bursting at the seams (32 pages of angry missives at the last count) with hundreds of outraged early adopters complaining that the sensor is borked, and that their lugholes are causing the phone to do all sorts of random stuff whilst pressed up against the screen.
These users are reporting droppped calls, unwanted conference calls and attempts to start Face Time video calls all while the touch-screen is supposed to be inoperative.
Apple is suggesting that users wipe their handset and start with a fresh install, especially if they have updated from a previous iteration of the iPhone.
Despite following the advice, a number of forum posters are reporting that the problem persists.
We haven't been able to replicate the flaw, but we might just be one of the lucky ones.
Add this to poor Wi-Fi reception caused by covering the antennas (or holding the phone the wrong way as Apple would have it) and discoloured screens, and the iPhone 4 is starting to look like it might have been slightly rushed into an overly eager market.
Which is a shame because, other than that, it's actually rather brilliant.