I also have this problem and it's pretty frustrating. I find myself typing poorly and spending a lot of time fixing typos. My son has a g75 also and he says my keyboard is worse than his - but it's very subtle. It seems to be hit and miss thing with G75's. It would take a long time to have my keyboard replaced, which I may do before long. Who knows if it will be better. In the mean time I've order a good compact mechanical keyboard.
I ordered the "Cooler Master CM Storm QuickFire Rapid." I'll post how it compares to my G75 keyboard. I expect it to be much much better. Even so, I'd still like to fix my G75 keyboard.
Just a note on mechanical keyboards. Many mechanical keyboards are available with different styles of mechanical key switches inside. Most of the key switches are made by one company and the style of switch is designated by color. I choose the "blue" style because they are best for typing - not gaming. The blue switches have better feedback in terms of feel and sound, but they are worse for activating on and off really fast. For gaming you'd pick a different "color." It's explained pretty well here:
http://mechanicalkeyboards.com/faqs.php?faq=mechanical_switch_differenceI love my G75, but I don't recommend it to friends because of the keyboard.