When these "lockups" occur, have you tried swiping JUST on on the gray unlock arch -instead- of swiping the whole screen?
The old Eris firmware would unlock if you swiped anywhere on the lock screen and that's what I learned to do. After the update, I too thought my phone was locking up on me. Swiping on the top half of the new lock screen does -nothing- and looks like the phone has crashed. I then noticed that it worked "sometimes" and finally figured out that you have to touch the gray arch and then swipe it.
Good luck.
The old Eris firmware would unlock if you swiped anywhere on the lock screen and that's what I learned to do. After the update, I too thought my phone was locking up on me. Swiping on the top half of the new lock screen does -nothing- and looks like the phone has crashed. I then noticed that it worked "sometimes" and finally figured out that you have to touch the gray arch and then swipe it.
Good luck.