First and foremost this is a nifty little addon, thanks for sharing this.
I've been trying to use this with Blender 2.74 and I got this error while trying to use it and then Blender just exits mesh edit mode:
Traceback (most recent call last):
File "C:\Path\to\Blender\2.74\scripts\addons\smart_edges_intersect_tool.py", line 82, in invoke
IndexError: BMElemSeq[index]: outdated internal index table, run ensure_lookup_table() first
location: <unknown location>:-1