I have been able to duplicate the iphone 4 reception problem with a bumper installed.
Hold it in right had fine, hold it in left had in the same spot bars drop off. EVEN WITH APPLE BUMPER INSTALLED.
I really think this has to do with an area that has weak reception in the first place because I have done this at other places and it doesnt move. Hence the reason some are reporting this and others are not.
I live in an area where I do get 3-5 bars, but when you were able to do the DB check the DB was weak. If the DB signal is strong it doesnt do this in my testing.
Hold it in right had fine, hold it in left had in the same spot bars drop off. EVEN WITH APPLE BUMPER INSTALLED.
I really think this has to do with an area that has weak reception in the first place because I have done this at other places and it doesnt move. Hence the reason some are reporting this and others are not.
I live in an area where I do get 3-5 bars, but when you were able to do the DB check the DB was weak. If the DB signal is strong it doesnt do this in my testing.