Hello there, 
First post  
  
I have encountered a strange symbol that affects lines: 
2 little blue boxes. What happens when i see these symbols, If I move a line and it's connected to other lines it will latch onto them and effectively drag them. 
I don't want it to do this, I don't know what to search for, spent a few days trying to find what it is because it nearly ruined a whole development! 
  
My boss is unsure what it is too. 
Running autocad 2013. 
  
Here's a picture: 
  
 
many thanks for help!