Pictures not shown when using special characters in Pagename

We are using xwiki enterprise and created a page name "MIO .NET" in a Space named Guides.
This page contains several Additional Pages for each chapter using the include function with "new context" option and defining the "MIO .NET" as parent of the additional pages.

When the page "MIO .NET" is now opened the Text is displayed correctly but the pictures are not loaded.

The created link for the corresponding Pictures is for example: http://xwiki:8090/xwiki/bin/download/Guides/MIO+.NET/codecom1.PNG.