trouble refreshing DBCTRLGRID in Delphi 3

Hello, I have some serious trouble here.
I work with Delphi 3. On a form I have a DbCtrlGrid and some
DbText-fields. On a datamodule I have a Table T1, a Datasource DS1
linked to T1, a query Q1 and for this query a datasource DS2.
For T1 I have set the property "CachedUpdates = FALSE !).
On my form I have also a button. When I click on it I do
With DataMod.Q1 do begin
   Close;
   Prepare;
   ExecSQL; //(Update DataMod.T1 Set T1.ammount = 1000)
   Close;
end;
When I click the button the query does its job, when I look in the
database the values have changed, so my query is not the problem.
After running the query I do DataMod.T1.Refresh, I also tried to do
DataMod.T1.Close and Open, but I don't see changes on my form. If I
close the applcation and reopen it, then everything is OK. It seems
that on the real table everything is OK, but my form is using some
CACHED table instead of the real one?
What is happening here ?
Please mail me at filip.will...@sidmar.be
Thanks for your help.