Does anyone know the difference between a Casio GW-M5610-1ER and Casio GW-M5610-1?

I bought the GWM5610-1 for my dad and he loves it. Can't beat it for the money. As far as the difference between the GwM5610-1ER, I'm not sure. They both say 20bar water resistant. Good question.

Nibiru has not yet arrived to take control of this planet. Soon! Until then, they will be made in Thailand.

Does the automic timing keeping able to work in Singapore or Malaysia?

Casio's answer is incorrect, and contradicts their own manual. You can use the "atomic" feature depending on two things: the city code you set, and the distance to the time transmitter. This watch does not enable "atomic" time for the Singapore city code, only for the Beijing and Hong Kong codes according to the manual. I assume Singapore is too far from the transmitter to receive the signal reliably, draining the battery. The situation is different for the transmitter in the US, it can reach large parts of Canada and Mexico, so if you set the watch to a Canadian or Mexican home city it'll try to receive the signal. New York is further away from the US transmitter than many Canadian cities. The same things is true in Europe, the transmitters in the UK and Germany cover most of Europe, so the watch will work just fine in France, Sweden, and probably even western Russia. Download the manual from casio.com for this watch and check for yourself, the module # is 3159.

Full auto el backlight with afterglow does not work.

Perform the official "Casio TILT test" to see if the tilt sensor that activates the backlight is defective:Hold down the 2 buttons on the left side of the watch and press top right button and the watch will enter TILT test mode. Place the watch flat on a table facing up. Pick up the watch and tilt it towards you, the screen should display number 8888. When you put it back down on the table, numbers should be cleared from the screen. If Tilt sensor is defective, no numbers will be displayed when you tilt the watch towards you.