Joomla does not find my plugin update

Question

I made my first plugin and want to setup an update site as well. My joomla does not find the update (after pressing clean cache of course). The update server is found and it load my xml. My manifest file:

<?xml version="1.0" encoding="utf-8"?>
...
    <!-- UPDATESERVER DEFINITION -->
    <updateservers>
        <!-- Note: No spaces or linebreaks allowed between the server tags -->
        <server type="extension" priority="2" name="ddVmSubs">http://danidek.hu/files/ddVmSubs-update.xml</server>
    </updateservers>
</extension>

The update xml file (ddVmSubs-update.xml):

<?xml version="1.0" encoding="utf-8"?>
<updates>
    <update>
      <name>ddVmSubs</name>
      <description>Subscription plugin of Danidek for Virtuemart. </description>
      <element>ddVmSubs</element>
      <type>plugin</type>
      <folder>content</folder>
      <client>0</client>
      <client_id>0</client_id>
      <version>1.0.5</version>
        <downloads>
         <downloadurl type="full" format="zip">My download link. I removed it because I can't post more than 2 links..</downloadurl>
      </downloads>
      <tags><tag>stable</tag></tags>
      <maintainer>Danidek Inc.</maintainer>
      <targetplatform name="joomla" version="3" />
   </update>  
 </updates>

I can't find out what is the problem.

Answer 1

Solved! I've changed the plugin file name and element name to lowercase. It started to work.

Answer 2

A very important thing for me was to set these two tags:

<folder>content</folder>
  <client>0</client>

In my case, the folder was "hikashop", because I made a plugin for hikashop, and the client 0 was "Administrator", so Joomla will show the update in the back-end.