Welcome to iPhoneForums, Paul!
Here are a few more things to try:
Force close the app where it's not working: double tap the Home button to show the multitask bar, then slide the picture above the app icon towards the top of the screen.
Reset your device. This won't remove data or settings. To reset, press and hold Home and Power button until the Apple logo appears. Let go of both. Your device will power up on it's own.
Go to Settings - General - Keyboard. Disable dictation and enable it again.
Turn on Airplane Mode and disable it after a few seconds.
Reset all Settings in Settings - General - Reset. This will set back all the settings to default, and you'll have to look through the Settings app afterwards to select everything as you prefer it.
Hope that helps.