Bad quality of custom made graphics in PS?

Hey there,
I've been working on a weblayout that soon will be coded. But there's an issue ofc. The layout I'm doing contains a lot of graphics and colors, gradients etc.
Check this image out, I zoomed in and took a screenshot.



Sorry, can't make urls here before I got 5 posts.

Check out the sides of both images.
They are custom made and no jpegs has been done or something like that.

I've had this problem before, when doing gradients there is like big quality issues in photoshop. Could it be because of the resolution? The resolution on the PSD file is currently 72.

Anyone got any ideas what this is caused by?

Thanks in advance,
Simon