Thanks for the tip Shootist007, you made a good point about Photoshop and the 16Gigs of mem.
So I followed your advice and copied several gigs back and fort between an external disk and the Macbook. I even downloaded the song that every one talks about that also triggers the fans when you play it for a while. But no luck in the office I don't get the fan spikes.
I started to test what happens if the Macbook runs on its battery only to test the power cord and its grounding theory. And now it becomes very weird even on battery I don't get the fans to spike noting nada... but this morning at home and yesterday in the evening the fans went ape **** crazy. With every copy action the fans would go to the max...
Next I went searching for another explanation, and the only other difference between home and the office is that in the office I'm next to a big window much light and my keyboard backlit is forced of. I only used the laptop at home with backlit keyboard on as I can recall, because it was late in the evening or early in the morning.
So I covered the sensor, enabled the backlit and run the same tests and the fans spiked in the office.
I know about the Sandisk - Samsung explaination but I'm still a bit dazzled getting the Macbook fans not to spike, before I messed with the backlit and bright sensor.
It seems so incredibly far fetched to me.