I hope the issue doesn't affect your particular model, but its probably better to know about it than to find out by having it fail.
I think this is the link about a heatsink mod for 8400GS m1330s.
Here is another discussing repairs. And another
As a long-time PC service tech, I'd just like to say that a few instances of fan failure in high-end, compact notebooks is by no means an indication of poor design - it's just part of the equation. You cram a lot of high-end hardware into as small a space as possible, make it portable, and throw some barely adequate cooling on it (penny-pinching OEMs), you're going to have thermal problems regardless of how well you've designed your cooling solution.
Plain and simple: laptops have thermal issues (more so than desktops).