dst.DbCancel() method is absolutely unworkable.

The most often error "Attempt to read protected memory"after that
application crash. Sometimes it causes application to shut down silently.
Sometimes it seems completed normally with expected error "Retrieve failed
due to database error" but any attempt to do any sql query after that causes
application hang.

E.g. standard SqlCommand.Cancel() is working correctly without any problem.

I am using dw.net_2.5_8209