I was sent a file which causes F.H. to freeze if you go into the Place List dialog, click on 'Reverse Display Order', and then try to sort on any of the columns. It turns out that the problem arises if (and only if) some of the place names include commas that have spaces between them (and nothing but spaces). For example,
Balerno, , Scotland
would cause the bug, but
Balerno,, Scotland
is OK.
Simon Orde List Administrator & Family Historian designer