not a legal OleAut date / diagram

Hello!

I am using SQL Server and SSRS 2008R2. I have a dataset on a report, which returns 5 columns:

Time_ID (datetime/date), Value_1, Value_2, Value_3, Value_4

I use this dataset for a line diagram, that shows the 4 values over time. The query for the dataset is a stored proc that uses a dynamic query, inserts the results of the dynamic query into a table variable and does a "select *" on this table variable to return the data. Datatypes in the table variable are correct.

Everythings works fine, until one of the 4 values reaches a certain value - then I get an error message instead of the diagram: "invalid OleAut date" ("unzulässiges oleAut Datum").

Anybody has an idea about this?

SSRS log file:

reportrendering!ReportServer_...:: e ERROR: Throwing Microsoft.ReportingServices.ReportProcessing.RenderingObjectModelException: , Microsoft.ReportingServices.ReportProcessing.RenderingObjectModelException: Not a legal OleAut date. ---> System.ArgumentException: Not a legal OleAut date.

Thanks in advance, maffman