The GF 4 440 go does have a pixel shader engine, but you will need to get the latest drivers on your laptop.. which is not always possible.. nVidia drivers dont update vaios/toshibas etc.
Sorry but only the 4200 series has pixel shaders, the 4xx Go ones don't. Simple as that.
OH YEH.. once again another lovely confusing page from nVidia.. it lists the GO series and mentions the Pixel shader directly beneath it..
Personally I think this a breach of trading and advertising standards, i.e. false advertising with intent to decieve.