iOS 4.0.1 for iPhone and 3.2.1 for iPad are released

Apple has improved the formula to determine how many bars of signal strength to display. On 15 July 2010 Apple issued iOS 4.0.1 including only this fix. It is available for the iPhone 4, iPhone 3GS, and iPhone 3G.
This release of iPhone came a day after Apple released a beta of a different update, iOS 4.1, to developers. That forthcoming update is expected to include a number of fixes that go beyond the reporting of signal strength on the iPhone.

The cosmetic software fix, however, does not address antenna issues that some users have experienced specifically with the iPhone 4 hardware. Apple is expected to reveal its reaction to that issue at a press conference scheduled for 10 a.m. Pacific Time on Friday.

There was no indication that iOS 4.0.1 will address the proximity sensor issue that has affected some iPhone 4 owners. The problem can cause the phone's touchscreen to become active while on a call, causing users to accidentally place a call on hold, end the call, or choose another option on the display.
According to Apple, iOS 3.2.1 for the iPad includes a number of fixes as follows:

1. Addressed an issue that could cause video playback to freeze
2. Improved Wi-Fi connectivity
3. Added Bing as an option for Safari's search field
4. Fixed an issue that could prevent copy and paste of single-page PDF attachments in Mail
5. Improved reliability of video-out when using iPad Dock Connector to VGA Adapter

While Apple quickly issued an update, as promised, for the iPhone 4 bar issue, the iPad update took more time. Apple had originally revealed that a fix for Wi-Fi issues was forthcoming in May.
A number of users have reported dropped signals and connectivity issues with the iPad when connected to a Wi-Fi wireless network. The IT department at Princeton University said the issue occurred because the iPad would continue to use a network-assigned IP address after it had expired.

The tests of iOS 3.2.1 were more focused on the Wi-Fi connectivity and below the test goes:

The test was performed on below Device variations:

1. iPad #1: WiFi/3G, 32GB Flash, WiFi via Broadcom BCM4329XKUBG, iOS 3.2 / 3.2.1
2. iPad #2: WiFi-only, 16GB Flash, WiFi via Broadcom BCM4329XKUBG, iOS 3.2 / 3.2.1
3. Router: NetGear WNDR3700, firmware 1.0.4.68NA, 2.4GHz / 5.0GHz

6 Tests were conducted to obtain the accurate result:

1. Test 1: Open field, iPads 20ft away from the router
2. Test 2: Open field, iPads 40ft away from the router
3. Test 3: Open field, iPads 60ft away from the router
4. Test 4: Router inside a house, iPads 20ft away from the router (1 wall between the routers and the devices)
5. Test 5: Router inside a house, iPads 40ft away from the router (2 walls between the routers and the devices)
6. Test 6: Router inside a house, iPads 60ft away from the router (backyard, more than 3 walls between the routers and the devices)