Apache vhosts and directories

[Mordecai]

Currently, I have this vhost set up:

<VirtualHost 12.218.96.144 [url]www.caiphp.com[/url]>
    ServerAdmin [email][e-mail][/email]
    DocumentRoot "D:/Apache/htdocs/caiPHP"
    ServerName [url]www.caiphp.com[/url]
    ErrorLog logs/caiphp.com-error_log
    CustomLog logs/caiphp.com-access_log common
</VirtualHost>

However, sometimes (not all of the time), my directories on the server will become something like this:
http://www.caiphp.com//index.php
Note the two slashes. What could cause this?

[Mordecai]

It's been a while, I figure this needs a bump to the top.