I have 2 tv shows with an ampersand character in the directory name containing the show files.
I have named both directories exactly like the name listed in thetvdb.
One is recognised and scrapes correctly, the other one doesn't and picks up the wrong show.
The one that works seems to have picked up an IMDB id, and so perhaps (?) that's why it works.
For testing, here are the 2 tv shows:
1. Works: Sex, Lies & Michael Aspel
2. Fails: Best & Worst Places To Live
For the one that fails it seems to be picking up 'Best Evidence' instead.
EDIT: I'm trying to fix the show entry in CM now by pasting in the id from thetvdb and it seems to have now pulled in the correct show info. But for bug fixing, this still might be of interest to improve CM.