OMA download descriptor

Hello,

  I got a problem while trying to create a proper download descriptor for a *.sis file. I'm following the "Content_Download_And_OMA_DRM_Examples_v2_2_en" example from forum nokia. When I try to download a sample image (image/jpeg type) everything works fine - the image is downloaded and saved properly. However, if I change the mime-type to application/vnd.symbian.install, the problem occures. Download descriptor is downloaded properly, the information about item being downloaded is shown properly, too. After the application is downloaded, the phone says that this type of content is not supported. Note that I tested this on both Nokia 6630 and 6680. Here's the download descriptor content:

<media xmlns="http://www.openmobilealliance.org/xmlns/dd">
<objectURI>http://proper_ip_address:7080/content_test/rain.SIS</objectURI>
<size>27162</size>
<type>application/vnd.symbian.install</type>
<name>Rain Application</name>
<vendor>SMTSoftware</vendor>
<description>OpenGL Rain Application</description>
<installNotifyURI>http://proper_ip_address:7080/content_test/Post</installNotifyURI>
</media>

  Any ideas what could be wrong? As far as I know these phones should support SIS OMA download OTA.

  Thanks in advance,

Damian