About every 10th request gives us a 404:
curl -s -i https://adwords.google.com/api/adwords/cm/v201406/CampaignService?wsdl | more
HTTP/1.1 404 Not Found
Content-Type: text/html; charset=UTF-8
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: Fri, 01 Jan 1990 00:00:00 GMT
Date: Mon, 01 Sep 2014 12:56:04 GMT
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
Server: GSE
Transfer-Encoding: chunked
<HTML>
<HEAD>
<TITLE>Not Found</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<H1>Not Found</H1>
<H2>Error 404</H2>
</BODY>
</HTML>