Sorry, but yes, it is a problem
I'll respectfully disagree. I have the same issue in my galaxy tab, and I've tried several others, this behavior is found in just a few.
I've made a video and a drawing test to illustrate it. I've put them in a page in a domain that I own.
(XDA still doesn't allo me to paste a link, but the address is fgfaria.com )
I've tried an app called touchscreen booster, which appeared to be appropriate from its description, but didn't notice any difference.
But there is a very intriguing point. It doesn't look like it's a hardware problem. I have installed touch test app, and with that the touch is perfect, no shaking. Also, specifically in youtube app, when scrolling the list of videos, it doesn't happen.
I need to find out why it happens pretty much everywhere, but not on youtube app and touch test apps.
Just to make it even more complex: as you'll see in the picture in the url above, towards to the right edge of the screen the problem is much lighter or doesn't happen.
If someone can help, that would be hugely appreciated!