Thanks, this worked for me!
Yet if you're using other mods which add placeable blocks (let's say Bibliocraft), you'd have to place them again, which make this a partial solution.
The problem is in 1.7.2 it doesn't 'deal with it himself'. You just can't load the world if you've removed any mod you used to have.
The ids the log is referring to are all the ids from the mod. I had no placed block in my world, i removed them all.