Touch Screen Issues 
Touchscreen phones require your fingers to tap the device and navigate applications, settings and functions. They are ideal for individuals who don’t want the hassle of inputting data via small buttons. But the phones are not problem-free and they require a learning period to get used to them. 

On-screen Keyboard Issues 

Most common problems are difficulty in entering data, sending text messages and navigating the device. Using the on-screen keyboard is a challenge for people who can’t use the small keys. 

Sensitivity Issues 

Touch screens are sensitive, and you don’t have to completely touch the screen to select items, tap links and complete functions. This is an issue that can lead to you accidentally selecting a function such as delete and erasing an email or document. You may or may not be able to adjust your touch screen mobile phone’s sensitivity setting 

Screen Size 

The lack of a large LCD or LED display screen is other disadvantage of touch screen mobile phones. The device’s screen is smaller than a tablet computer and doesn’t allow you to view an entire website, document or other file without scrolling down with your finger.  

Accidental Dialing 

Touch screen can be engaged so easily, it is easy for users to call contacts accidentally -- even when the phone is in your pocket. Most phones have a lock feature that requires you to slide a bar across the phone to unlock the touch screen. However, some phone do not have this feature and on some phones this feature is not secure enough.