Vcl50.bpl error on showing a sort DataSet in QuickReport

I'm opening a MSSQL Server 7.0 table by a SQL instruction thru the DataSet's CommandText property. In that instruction I order the fields thru the clause Order By.
In the Form, I give the option to order the DataSet by another criteria (by another field). When the user choose the option, I order the DataSet by the Sort instruction like this:
DataModule.DataSet.Sort := 'Field ASC';
When I try to show the DataSet in a QuickReport, the first time it shows the results ordered, but the second time I run the QuickReport it causes the following error:
'Access violation at address xxxxx in module 'Vcl50.bpl'. Write of address xxxxx.'
'Project xxx faulted with message: 'privileged
instruction at xxxx'. Process Stopped. Use Step or Run to continue.'
I'm using Delphi 5.0, with Delphi 5 Update Pack 1 Enterprise Edition and Delphi 5 ADOExpress Update Pack 2 installed.