Error de memoria al llamar otra form

[dmagui]

Código Delphi [-]
 try 
varform26.ShowModal;
DBEdit1.Text:=unit27.varedit;
IBDataSet1.Active:=True;
IBDataSet2.Active:=True;
IBTable1.Active:=True;
IBTable2.Active:=true;
IBDataSet3.Active:=True;
except
varform26.free;
end;