Crash after mouseover subreport

Hi,

I create a Report with a Subreport.

The Subreport Show me data from my Access Database. The Problem is, when i go with my mouse over the subreport data, the Report Crash with the follow german error:

Untergeordnetes Fenster kann nicht auf der obersten Ebene erstellt werden

english Translation:

Child window can not be created at the top level