If this was really a wall, wouldn't it be blocked because the wall is thicker then a normal line.

The walls print thicker than the grid lines, but they don't represent something thicker. Although they may appear thicker (or slightly longer) than the grid segment they overlay that's just an optical effect and has no impact on LOF.

Thanks, I've been playing that wrong since I started out. Someone told me in one of my new player days and its believable so I never questioned it.

Sounds to me like you need some dental floss, or, because we had none at the time, some lengthy soft YARRRRRRRRRGHHN!!!!!

Yeah, you do have line of site, as the others have stated.