Re-run the assessment, the point ss202sl makes is true. I have an old build with an HD 3000 (ati, integrated) that scores a 4.4 and a HD 4200 (ati, integrated as well) that scores a 3.8. The HD 4200 really is the better integrated video card but it gets a lower score for some reason. I noticed my HD 3000 scores fluctuate, every time I re-run the assessment (not subsequently but separated by a day or two) I get scores ranging from 4-4.4 for it.
Point being made is WEI is not the best tool to measure the performance of your computer. I would also recommend you upgrade your drivers and re-run the test after that.