Being jailbroken on a last generation iPod Touch 4g, I would say I have a little bit of experience in iOS theming. In the following pictures, both themes did once work fine on the previously mentioned device.
The weather widget theme is Blacksand. As you see, there is a black bar at the bottom.
In this picture, the slider is Nobelis HD. You can faintly see a grayish line at the same point where the black bar starts in the previous picture. Also, the camera button is weird. There are no other Winterboard themes enabled. A guess for this problem is that I may have an outdated version of Nobelis. I don't know.
NOTE: The grey bar is not apart of the wallpaper.
Also, i have been trying to use a weather widget theme on my Homescreen with a similar problem as the first picture.
Thanks in advance.

The weather widget theme is Blacksand. As you see, there is a black bar at the bottom.

In this picture, the slider is Nobelis HD. You can faintly see a grayish line at the same point where the black bar starts in the previous picture. Also, the camera button is weird. There are no other Winterboard themes enabled. A guess for this problem is that I may have an outdated version of Nobelis. I don't know.
NOTE: The grey bar is not apart of the wallpaper.
Also, i have been trying to use a weather widget theme on my Homescreen with a similar problem as the first picture.
Thanks in advance.