[pmwiki-users] Need help troubleshooting (ScriptUrl?)

[Pico]

A post on the Questions page identifies a site that appears to have an
odd install issue that needs troubleshooting.  (This is not my own
Question).  The problem appears to be related to the ScriptUrl.  Here
is a quick summary of how the url changes in response to various
actions:

1. Initial visit (and subsequent clicks on PmWiki Logo)
http://www.bynw.com/wiki/pmwiki.php

2. Click on HomePage (or View) links:
http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage

3. Click again on HomePage (or View) links:
http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage?n=Main.HomePage

4. And again...
http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage?n=Main.HomePage?n=Main.HomePage

Notice the pattern of appends.  The same thing happens with edits, only
the action string in included:

1. Initial visit (and subsequent clicks on PmWiki Logo)
http://www.bynw.com/wiki/pmwiki.php

2. Click on Edit:
http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage?action=edit

3. Click on Save (or Cancel, or Preview):
http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage?action=edit?n=Main.HomePage?action=edit

Note that the edit screen remains posted and subsequent clicks will
append ?n=Main.HomePage?action=edit again, and again.

Finally, I added some page variables and note that the value of the
ScriptUrl keeps changing:

1. Initial visit (and subsequent clicks on PmWiki Logo)
Address bar is http://www.bynw.com/wiki/pmwiki.php
{$ScriptUrl} is http://www.bynw.com/wiki/pmwiki.php 
{$PageUrl} is http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage

2. Click on HomePage (or View) links:
Address bar is http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage
{$ScriptUrl} is http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage 
{$PageUrl} is
http://www.bynw.com/wiki/pmwiki.php?n=Main.HomePage?n=Main.HomePage

I won't be able to check the list tonight, but if someone comes up with
the answer, please add it to the questions page.

Pico