Daylight Sensor providing power in incorrect circumstances

It was night and I was surrounding a light detector with a pyramid of TNT. I put one piece on each side of the block, when I put a TNT block on top of the light detector, it delayed, then activated the TNT. It was still night time. I tested the bug with other blocks. IT works with red stone lamps also. it will not work with pistons, so I don't think that it only happens with red stone items.

What I expected to happen was...:
What I was trying to do is wait until day and watch the TNT blow up.

What actually happened was...:
The TNT activated when it was not supposed to.

Steps to Reproduce:
1. Place Light detector
2. place a block or blocks of certain types on each side of the light detector
3. Place block on top of light detector for it to actovate