ObjectDataSource not working in design time

[Jorge]

I have a dataset with a datatable (that gets data from a simple sql query).
If I connect a new report using an objectdatasource to this datatable, fields are not shown in "Report Wizard" neither in "Edit Expression".
Even I preview the report I get "An Exception has been thrown by the target of an invocation".

If, however, I use SQLDatasource everythings works fine.

Any idea?
I'm using 2010 Q1

Thanks!