Gradients Being Cut Off

[Krimm]

SMF Version: 2.0 RC3
Theme: Impulse RC3

Alright, I decided to change the gradient on my forum to something a bit sleeker that would generally look better. It was curved left and right endings, but when I added them to the forum, some of the gradients would show the curved edge but others would just act as if it didn't exist.

Example: Click

There is probably a painfully simple solution to this problem, but I'm really quite new when it comes to working with the SMF setup so any and all help will be greatly appreciated.

Thanks!

[ARG01]

When altering the main_block.png file try adding another layer under the sections that you changed and give it a color that is the same as your main background color.