Hi,
I had a very similar problem with my phone after I installed the update, however mine was whenever I tried to play music.
I started a thread not long ago which has a few tips and ideas. The main reason we think mine went into crash mode is because I installed the update whilst the phone was on charge, which I have now found out it does warn you not to do before you agree to update. Was your phone on charge whilst you updated?

 

Hi,

The same thing happened to me.

Although I also rooted the phone.
So I am not sure what the cause of the issue was.
Although youtube and games were working when I first got the phone.

I have since sent the phone back for repair / replacement.

I was able to revert the phone back to the stock flash, but it was still in an unlocked state.

I wonder if it will effect me in trying to get the handset replaced.

If having the charger connected while installing an update causes a problem, perhaps they should prevent update if a charger is connected.
Makes sense to me, although hmmmmm may not make sense to the developers.