You must see the screens to understand:
1.Bug:
Pulling the lever affects a 1-tick signal at the left repeater
2.Bug:
Placing a minecart on the rail, pull the lever affects that the left repeater is still powered, but the right isn't
3.Bug:
Placing a block in front of the rail (lever: off) will affect that the left repeater is powered; BUT: removing the block doesn't change anything
4.Bug: placing a minecart on the rail pulling lever on and then off an now change a block next to the rail (for example place redstone next to it) will affect a redstonesignal