--- Operating System, Graphics card ---
Win7 RadeonX850


--- Blender version with error, and version that worked ---
2.65a; none other tried so far


--- Short description of error ---
After trying to join 2 meshes with the boolean modifier and then applying, the error indicated on the pictures occured
picture#1 is in editmode
picture#2 is in object mode

--- Steps for others to reproduce the error (preferably based on attached .blend file) ---
make 2 meshes with hole(s) in them, then make them overlap, then add boolean modifier to one of them (use difference(?)), then apply it, then select the other one, then enter editmode