Contacts button and Start menu item not responding

Since "Contacts" on the start menu fails at the same time as the button, it is more like that there is a software problem, and the button cannot open the applet that is failing. If you want to ensure that you do not have a hardware problem, try remapping the button to open another application. You can do this by going to Settings/Buttons.

You might want to try using the Task Switcher, which you can turn on in Settings/System. When you encounter the problem with Contacts, then click on the Task Switcher and see how many programs are open. Use the Taks Switcher to close all the programs, and then try Contacts again and see if it works. Most applications do not close, and if you have many open applications, then it will degrade performance.

I encountered the same problem - cannot open "Contacts" in any way; problem remains unresolved.