WordPress MU

HELP!! Running 2.6.1 and XMLRPC appears completely broken. I can browse to http://server/xmlrpc.php and http://server/blogname/xmlrpc.php and both give the appropriate:
XML-RPC server accepts POST requests only. response.

BUT when I try to run even the simple demo.sayHello to test, I get an error:
XML-RPC server accepts POST requests only.

If I change my host to any of my non-wpmu wp blogs, I get the expected hello response. So this is limited to WPmu. I am running with subdirectories. The code I am using is about as simple as it gets (and, as I said, works fine if I change the url in the code to a single-user WP installation):

include('IXR_Library.inc.php');
$client = new IXR_Client('http://domain.dom/chris/xmlrpc.php');

if ( $client->query('demo.sayHello') )
	{
echo '<pre>';
print_r($client->getResponse());
echo '</pre>';

     } else {
  die('An error occurred -
'.$client->getErrorCode().":".$client->getErrorMessage());
}

Go to Setting -> Writing. Scroll to the bottom. Check the ticky box, see if that helps.

Both boxes are checked. Everything appears to be in order as far as the settings go, and I have tested that the sayHello command works in other WP installations both single and WPmu, but I don't know of any others using sub*directories* can test with...

I've enabled logging and this is what gets logged when I try to connect with Livewriter

Input: <?xml version="1.0" encoding="utf-8"?>
<methodCall>
 <methodName>blogger.getUsersBlogs</methodName>
 <params>
  <param>
   <value>
    <string>ffffffabffffffce6dffffff93ffffffac29ffffffc9fffffff826ffffffdeffffffc9ffffffe43c0b763036ffffffa0fffffff3ffffffa963377716</string>
   </value>
  </param>
  <param>
   <value>
    <string>username</string>
   </value>
  </param>
  <param>
   <value>
    <string>password</string>
   </value>
  </param>
 </params>
</methodCall>

2008-10-07 21:05:38  Input: <?xml version="1.0"?>
<methodCall>
<methodName>wp.getUsersBlogs</methodName>
<params>
<param><value><string>username</string></value></param>
<param><value><string>password</string></value></param>
</params></methodCall>

Where username and password are the correct username and password.

Here's a log from a working installation... everything looks right, but the former dies:

Input: <?xml version="1.0" encoding="utf-8"?>
<methodCall>
 <methodName>blogger.getUsersBlogs</methodName>
 <params>
  <param>
   <value>
    <string>ffffffabffffffce6dffffff93ffffffac29ffffffc9fffffff826ffffffdeffffffc9ffffffe43c0b763036ffffffa0fffffff3ffffffa963377716</string>
   </value>
  </param>
  <param>
   <value>
    <string>username</string>
   </value>
  </param>
  <param>
   <value>
    <string>password</string>
   </value>
  </param>
 </params>
</methodCall>

2008-10-07 18:09:02  Input: <?xml version="1.0" encoding="utf-8"?>
<methodCall>
 <methodName>blogger.getUsersBlogs</methodName>
 <params>
  <param>
   <value>
    <string>ffffffabffffffce6dffffff93ffffffac29ffffffc9fffffff826ffffffdeffffffc9ffffffe43c0b763036ffffffa0fffffff3ffffffa963377716</string>
   </value>
  </param>
  <param>
   <value>
    <string>username</string>
   </value>
  </param>
  <param>
   <value>
    <string>password</string>
   </value>
  </param>
 </params>
</methodCall>

2008-10-07 18:09:05  Input: <?xml version="1.0" encoding="utf-8"?>
<methodCall>
 <methodName>wp.getCategories</methodName>
 <params>
  <param>
   <value>
    <string>1</string>
   </value>
  </param>
  <param>
   <value>
    <string>username</string>
   </value>
  </param>
  <param>
   <value>
    <string>password</string>
</value>
  </param>
 </params>
</methodCall>

2008-10-07 18:09:07  Input: <?xml version="1.0" encoding="utf-8"?>
<methodCall>
 <methodName>metaWeblog.getRecentPosts</methodName>
 <params>
  <param>
   <value>
    <string>1</string>
   </value>
  </param>
  <param>
   <value>
    <string>username</string>
   </value>
  </param>
  <param>
   <value>
    <string>password</string>
   </value>
  </param>
  <param>
   <value>
    <int>1</int>
   </value>
  </param>
 </params>
</methodCall>

make sure it's enabled on the main admin blog as well.

I did... it's enabled in the main and the sub blog

I discovered the problem-- it's the gt search all blogs plugin (http://wpmudevorg.wordpress.com/project/GT-Search-All-Blogs) I have no idea why, but when I have that plugin installed it is borking the XML-RPC... maybe some variable getting clobbered? I don't get it.

I'm having the same problem and we're not running that plugin. Heck, I've disabled all the plugins on the test blog and still not working.

andrea_r, just to chec, which check boxes were you specifically talking about? The Settings > Writing admin page only has the checkboxes for:

• Convert emoticons like :-) and :-P to graphics on display
• WordPress should correct invalidly nested XHTML automatically

Edit
BAH! I just checked our 2.7 bleeding edge test server and I see the Remote Publishing settings in the admin there.

Wonder why they aren't showing up on the other server...