I use Acer 4530.
This problem has happened long since Ubuntu 10.10 and now that I use 11.04 dual booted with Linux Mint 10. Everytime I press one key repeatedly, like when I read a long article in a website/ebook or when I play games which required me to press arrow keys repeatedly, it would randomly freeze. That is, whatever I press on keyboard has no effect, and that also happens with touchpad. However, the USB mouse works just fine. I later found out that it's not actually freeze but more like it's like the key stuck. For example when I play tetris which I usually press w (down) button repeatedly, after some times it would freeze. And if I put the cursor in, say, browser's address bar, it would type "wwww....." infinitely.
The only way I could fix it is by suspend the laptop, either by using mouse or by closing the lid. And instead of suspended, in that case the laptop would automatically wake up and everything will be fine. (Usually my laptop would wake up after suspended by pressing any key)
It has happened since the first time I use Ubuntu, 10.10, and it also happens in Linux Mint 10, and until now in Ubuntu 11.04. It never happened when I use Windows, though. Anyone has ever encounter similar problem? Anyone know how to fix it permanently?
I just recently installed Windows 7 and Windows 8 Development Preview and both have similar symptoms. So I declare that this problem is not OS specific, probably hardware problem.