Content originally posted in LPCWare by kwinchell on Tue Jun 18 14:11:06 MST 2013It sounds like you solved your problem.
But for the benefit of others who might never be getting their I2C interrupt, Check how you left the state of your AA Flag.
If you cleared this flag (LPC_I2C->CONCLR = 1 << 2, or LPC_I2C->CONCLR = 4), then it will not receive a new command, and no interrupt.