I have received the 8gb ddr3 memory from the United States but unfortunately it does not work on my laptop although it is certified to be PC3-1333. I do find it very strange because there's no apparent difference in the installed memory on my laptop and the memory which I have bought through ebay (and the seller is in the USA). Anyway, I had to do a RMA refund before sending the memory back to the seller. I think the difference is that the memory which I have bought from the USA does not bear any popular branding, unlike the Kingston and the Samsung module which is pre-installed on the laptop.
Coming back to the issue of buying memory from the Crucial webpage... Initially I was on ebay again and I have found out that the cheapest 8GB DDR3 memory which I can find was around £160 (seller is in the UK). I don't think I can afford the money although it was Kingston branded. I could also choose Hynix branded but it will cost around £168. At the bottom of the page on ebay, I saw Crucial's advertisement. I then went to their website to take a look.
To my surprise, the 8GB DDR3 sodimm kit (2x4GB) only cost around £86 including postage! The best thing is that the company is based in the UK! I was delighted and so I made a call to make a purchase. Not to my surprise, I was being charged £108 instead! I called this morning to clarify and indeed I was being charged for more! The Crucial customer service was efficient and my case was solved! I did not call in but instead used the page' Live Chat. It worked! Curcial customer service is excellent!!!
17:57 - The memory is holding on perfectly! I do like it because Hardware Monitor Pro is showing the memory's temperature! It did not show when I had both Kingsont and Samsung chip inside previously. With the 8GB PC3-10660 installed, Windows Exprience Index showed an increase of 1.4. It is now 7.1! My next target will be an Intel Core i5 520m cpu for the laptop.
16/12/2010: - The 2x4GB memory from Crucial is perfect!!!