I'm having the same problem and came to search for help.
I have a samsung galaxy nexus and the stock browser keeps refreshing when it loads the homepage (google.com)
It's not possible to type anything in the search bar because it just keeps refreshing, unless you tell it to stop loading.
After loading another site (either followed a google result link or wrote another address) the browser closes with no error messages.
Yesterday the whole device froze as well as I tried to unlock it. The power and sound buttons worked still, so I tried to shut it down, but the touch screen didn't respond, so I had to take the battery off.
I'm having a ton of problems,as opposed to none, since the 4.2.1 update it got.
And since I'm at it, the calendar isn't updating the newly added contact events (birthdays,anniversaries, etc...) They're syncing right away with the google account, but not with the phone calendar.