Sorry, but you're both not understanding the issue - either that or you're deliberately leading me on, I will play along for now.
Not leading you on, no need to start getting defensive..
What we're trying to say is the grid is just a picture overlay on the screen, the level is cpu generated from the sensor, in real time.
The grid should always be correct with the screen - it's just a picture being shown.
The level should be correct with the horizon.
All three should be correct with each other.
So:
If your level is right with your grid but not the horizon that indicates the screen is out.
If the grid is right with the horizon but the level is out indicates a sensor malfunction.
If all three are mismatching then your camera is buggered..
You did say the the grid and the level were OK, I said it indicates the screen is off whack.
Four tests:
1 - take a picture of a level fence, your eye only.
2 - turn on grid, take same picture, use grid to line up with fence.
3 - turn off grid, turn on autolevel, use that to level camera, ignore what your eyes see on the fence.
4 - turn on grid AND level, use both (see if level matched grid) to take picture.
Now look at them on a computer screen (not the camera - it might have an out-of-level screen).
All should be level.
If #1 is out it's your eyes.
If #2 is out it's the screen being out (remember, the grid is just a projected image).
If #3 is out it's the level buggered.
If #4 is out AND the level and grid matched then it's the screen that's out of whack.
The grid overlay is the final decider - it's accurate and projected on the screen from a fixed image. If the level matches it, the screen is wonky. If the level doesn't match it, the level sensor is wonky.
The grid lines are a display on screen, the electronic level is a display on screen - I get that. The fact is when the level indicates - by changing to green - that the camera is level, it is not level. The screen is perfectly aligned both with the camera and the sensor. It takes perfectly level images when I level the camera myself. But IF I used the electronic level the pictures would slope - quite badly.
If you have an X10 try it out. When your level shows green is your camera level? If it is level then fine - you're lucky. If it isn't level you will understand what I mean.
Sorry if I'm not explaining myself well, perhaps I'll investigate how to post an image.