My iPhone has started freezing after I wake it an slide the switch to go to the password screen. Any ideas on cause or solution ?

Question

In the pas 24 hours I have begun experiencing frequent screen freezes when I attempt to in lock my phone.

Answer 1

You didn't mention anything that you may have done to trouble shoot the problem, so I will start with the basics.
Shut down all multitasking apps that may be running in the background.  They may be causing memory overload and not allowing the phone to function properly.
1. Double press the home button to open the multitasking tray
2. Tap and hold any app icon until they all start to wiggle and display the X button on each icon
3. Tap the x button to close the app
4. Repeat for all apps
5.  Press home button to close multitasking tray
Check to see if phone is functioning properly.
If not go on to the next step
Restart your phone (Kind of like restarting your computer when it starts to act all wonky.
1. Press and hold BOTH the power button and the home button at the same time
2. Continue to hold both buttons down for at least 15 seconds or until the Slide To Power Off screen appears and disappears
3. Wait for the silver apple logo to appear
4. Release both buttons and wait for phone to return to lock screen
5. Try unlocking the phone
If this doesn't work you may have a more serious problem.
At this point I would try to reset your network settings just to clear out everything that may be causing the phone to act up.
1. Settings
2. General
3. Scroll to bottom of screen
4. Reset
5. Reset Network Settings
Wait for phone to restart and see if it's working again. You will have to reenter your wifi passwords when you connect to a wifi network.
If not the last thing I would try is to do a Reset All Settings option.  This will set your phone back to its default state but don't worry, it won't erase any of your content.  At least it is not supposed to.  I have done this a number of times because of the battery life issue I picked up when I updated to iOS 5.0.1 and I haven't lost a thing.
You just have to reenter your passwords again and maybe turn off the things you turned off before, i.e. Siri Raise To Speak, Locations, etc.
1. Settings
2. General
3. Scroll to bottom of screen
4. Reset
5. Reset All Settings
Wait for phone to restart.  Go through the setup routine.  I normally do a set up as new phone when I do this to get back to factory defaults and then just set up the things I want on or off.
If none of this helps you may have an app that is causing the problem (Think back to the app you may have added just before this problem started and delete it to see what happens).
If that isn't the cause and if you phone is still acting up on you, you may have a hardware problem.  Time to head to the Genius Bar at your nearest Apple Store, assuming you are close enough to one.  Or go to the storew where you bought the phone, if you bought it at a physical store rather than online and have them look it over and see if you need a hardware replacement.
Good Luck.