Last year a design flaw on the iPhone 4 caused its signal strength to drop dramatically when the user's hand covers the phone's internal aerial. Apples answer was to provide users with a rubber band to protect the aerial.
But British boffins investigating the 'death grip' claim that believe cases or covers do not improve the failed signal. Mark Beach, professor of radio systems engineering at Bristol University said his team were able to identify the antenna problem for the first time.
There was a 100-fold drop in sensitivity of the phones when held in a particular way and this dramatically lowered the electrical match between the antenna and the handset's electrical circuitry. But a plastic cover 'did not affect or make any difference to the signal problems', said Professor Beach. Despite its technical faults the iPhone 4 was widely successful, which means that people were buying it not caring if it worked or not.