Run RedSn0w and point it at the 4.0 IPSW. (Yes – point it at the 4.0 IPSW even though you're at 4.0.1). This will also hacktivate your iPhone3G at 4.0.1 if you haven't already been activated by iTunes.
Install ultrasn0w in Cydia (add repository http://repo666.ultrasn0w.com) if you need a carrier unlock (and in the USA, remember to turn off 3G mode in Settings→General→Network).
Apple has just released iOS 4.0.1 for iPhone 3G, iPhone 3GS and iPhone 4. The free update fixes the issue with signal indication - the math formula to display the iPhone's service signal bars. Official changelog for iOS 4.0.1:
Improves the formula to determine how many bars of signal strength to display
The updates for the iPad OS 3.2.1 are:
Improved Wi-Fi connectivity
Fixed an issue that could prevent copy and paste of single-page PDF attachments in Mail
Addressed an issue that could cause video playback to freeze
Improved reliability of video-out when using iPad Dock Connector to VGA Adapter
Here is a video of a guy who tried to reproduce the antenna issue on the iPhone 4 with a latest iOS 4.1 beta. As you see, the smartphone loses two bars when he holds it with a "death grip", so it looks like the problem with antenna wasn’t actually fixed.
Guys from iPhoneHellas.gr report that iOS 4.0.1 may be released today. Such information was received from some "reliable" source, and it looks like true as earlier this site has already been proven to be reliable channel of information.
Last week our site iPhoneRoot.com was contacted by Wall Street Journal journalist to comment on recent iPhone antenna and signal issues. We certainly shared our thoughts. After interesting conversation we agreed to perform a research of the latest iPhone iOS 4 firmware. As a result WSJ published two interesting articles covering iPhone, antennas, signals and bars. Take a look:
iPhone 2G and iPod touch 1G do not officially support iOS 4. However there is a project called WhiteD00r that aims to bring iOS 4 functionality to iPhone 2G users with a custom firmware bundle.
This bundle is created by Matteo Morando and is based on firmware 3.1.3. It is built with PwnageTool. It incorporates several utilities to adds iOS 4 features such as multitasking, wallpaper, tethering, sms count, and more.
There are 3 different versions - Lite and Full for iPhone 2G and one for iPod touch 1G. Here is the complete feature list:
MuscleNerd from the iPhone Dev-Team announced via twitter that an unlock for iPhone 3GS with 05.12.01 baseband from iPhone firmware 3.1.3 will be released soon:
@MuscleNerd will there be a unlock software coming out for the 3gs 3.1.3 baseband 05.12.01 when the new iPhone 4g comes out??
@EmmanueGT yep..so don't sell or give away your 3GS (at same time, remember not to accept Apple FW upgrades in future)