Problem working with RTC DS1337.

If I look here: Mixed-signal and digital signal processing ICs | Analog Devices

You should also use pull-up resistors for intA en intB.

By the way, it also looks like your arduino uses a 5V I2C bus and your DS1337 is connected to 3.3V.

And is your I2C-adress for the DS1337 defined anywhere?