EDIT: The resistors must also be at the last device on your bus. Not at the microcontroller.
Is this really really important? I have been putting the pullups on an EEPROM I am using, but have subsequently added more I2C devices. I think some of them may not be in a line on the bus, but the SDA and ACL pairs run parallel from two different devices, with just one set of 4.7k pull ups. I am going to have to be more careful in my creations moving forward. I'm glad you mentioned that. Another good day, starting out learning something new.