'#' is special character in URLs marking the anchor reference (e.g.
http://server/file#anchor). Likewise if you save file locally with
name "places#1.kml" then it isn't loaded by GE running in Windows XP.
In fact I tried this test. Save one placemark (A) in one file named
'test.kml' and another (B) in another file 'test.kml#1.kml' both in
same directory. If you load file 'test.kml#1.kml' then test.kml with
placemark A is loaded.
Looks like '#' and text following is being stripped from file path.
If same file is served from web server and accessed with URL escaped
(# -> %23) (e.g.
http://server/kml/test.kml%231.kml) then GE still
fails to load the file.
Apparently Google Earth is not escaping the file names completely.
There was a problem recently with whitespace in folders or filenames
not being loaded.
This is a bug in GE, however, to use GE correctly this puts a limit on
what GE accepts in paths and filenames for KML/KMZ content.
Windows for example does not allow the following characters in file
names: \ (backslash), / (forward slash), : (colon), * (asterisk), ?
(question mark), " (double quotes), < (left angle bracket), > (right
angle bracket), | (pipe).
It is best practice to avoid %, #, and $ characters in file or path
names as these are commonly used as variable name prefixes, so it can
get messy if automating anything with filenames that include these
characters. If networking cross platform (e.g. Samba, SMB, CIFS)
consider effects of !+{}&[] on path and filename translation.
Reported this issue as a bug:
http://code.google.com/p/earth-issues/issues/detail?id=1126
--jason