Here is a great article for troubleshooting the multi touch display software issues.
iPhone, iPad, iPod touch: Troubleshooting touchscreen response
Use this article to troubleshoot the following iPhone, iPad, iPod touch Multi-Touch display (or touchscreen) response issues:
- Multi-Touch display (or touchscreen) does not respond
- Portions of the Multi-Touch display do not respond
- Multi-Touch display is very slow to respond
- Multi-Touch response is erratic
ResolutionIf your device is experiencing any of the symptoms listed above, try the following steps:
- Restart your device
- Hold the On/Off button until "slide to power off" appears. Slide to power off your device. When it is off, press the On/Off button to turn it back on.
- If you can't restart your device, reset it by pressing and holding the Sleep/Wake button and the Home button at the same time for a least ten seconds, until the Apple logo appears.
- Clean the screen with a soft, slightly damp, lint-free cloth.
- Avoid using the device while wearing gloves, with wet hands, or immediately after applying hand lotion.
- If you have a protective case, or if you are using a plastic sheet or film on the display, try removing them and testing the device without it.
Tip: To isolate an issue related to a portion of the Multi-Touch display, follow these steps:
- Open the Maps application and double-tap each corner, then the center, to verify that it zooms in to each section.
- If a specific area is affected in another application, note the location and try to verify touch functionality for that location in the Maps application.
On iPhone and iPod touch, you can also use Calculator:
- Open the calculator app to test all but the top row of the screen. Press each button on the calculator and verify activity.
- To test the area at the top of the screen, rotate the device to change to the scientific calculator and press the buttons in the left or right two rows.
When speaking with a Mac Genius or Service Provider, you can use this information to assist with evaluation of your issue.
All the best,