It would appear that I'm having a similar problem, if anyone has encountered this...
I've been using PPhlogger for about 3 years, and never encountered a problem until recently I cleaned up my site code - which makes it run a lot faster. Now, only about 1 in ten users showing up are being logged.
Additionally, if I want to track individual pages, I'm unable to by following links. Testing with myself, if I manually enter an individual address (say, downloads.php) and then click "refresh" it will show up. If I go via a link to the exact same address, and click refresh, it will not.
I moved the logger code to the bottom.php which is included in each page. Anyone encounter anything like this, or have any ideas?
Edit: Using st=img instead, I am able to always see the count when I go directly to www.twinrose.net
... However, if I go to www.twinrose.net/index.php
I get a broken image box (even though it's the same page!)