Sometimes when i use sponge on lava, it is still lighting the area. This is after i went using angel blocks and sponge above lava lakes left by ender quarry (world hole upgrade, no pump because it bugs) http://i.imgur.com/lvSKTqL.png

OpenBlocks-1.7.10-1.3-snapshot-513

If i backtrace the light to their source blocks with use of a stack of blocks replace all of them, only then the light goes away. While placing the blocks you can see which side of the blocks are brightest lit, so to know which direction to go.

try sending a block update by say placing a block, does it still leave it then?

strange.. :/