agree, its got to be hardware otherise a stock software restore to ios4 should eradicate the issue but it doesnt..
Out of interest...what are the serial numbers of your phones (for you guys experiencing the same issue as me) ..there may be a certain batch / week number that have the issue.. (just like the yellow tinting on the 27 inch imacs ! WHICH I ALSO HAD TO REPLACE MULTIPLE TIMES 😟 )..
here is what
http://www.chipmunk.nl/klantenservice/applemodel.html states about my iphone... its a week 23 build.
Name: iPhone 4
Group1: iPhone
Group2:
Generation: 4
ModelCode: iphone_4
Screen resolution: 940x640 pixels
Colour: Black
Capacity: 512MB
Factory: 84 (Shenzhen, China)
External link: Technical specifications by apple-history.com
Model introduced: 2010
Production year: 2010
Production week: 23 (June)
Production number: 658 (within this week)