Read more...doesn't work

Hi, I just installed CjBlog. Installation works fine (testsite http://epubjournal.de). But on articles the Read more... leads to a 404 error. I have a managed server with php 5.3. My providerfriends found out, that Read more.. works with php 5.2. But than the automatic update inside joomla doesn't work anymore. At the moment the account runs on php 5.2. to test the component. What can I do, to have it work with php 5.3.?
Regards Helmer from Dresden/Germany