lever not shutting off redstone from certain distance

When creating a redstone pistion device with the lever as it's switch, the pistons rise but when shut off, does not turn off redstone as previously done.

Not sure if this is a bug or if I am doing something wrong.

But when the redstone is only 2 blocks away from design, the level works fine, only when long distance but within the 15block limit it does not shut off.

I hope these screenshots help, before lever on is the first screen shot, lever off is the last shot. Notice the difference in lighting to determine power on and off. cheers.