Canon 430EX - not enough power compared to in-built flash

Hi everyone,

I am new to flash photography. I own Canon 30D and after reading reviews I bought a 430EX flash (580 EX II - expensive and bulky). I needed the flash to do indoor photography and felt the inbuilt flash was not powerful.

I tried few shots with in-built flash and with Canon 430EX. The images from in-built flash had more light than 430. Also the images taken in night potrait mode with in-built flash had more light than 430.

I had to increase the flash exposure compensation to +2 on the 430 to get more light in the images than the in-built flash.
Am I doing something wrong? Please do advice.
Thanks in advance