May be the proximityd is exactly the cause of the issues you've to deal with? Have you tried to remove it and test the response again?

In addition, are you sure the problem isn't caused by the refraction of the sreen protector under strong daylight? Have you tried punching a hole in where the screen protector is blocking the sensor?

P.S. Don't worry about the radioactive cloud from Japan. I read from local news that it'd take 6 days to reach where you leave, you still have plenty time to evacuate.