Violation on FOREIGN KEY constraint

I have almost reached the point of “Scream!” Running this code will return the error:

“Project Corp.exe raised exception class EIBInterbaseError with message ‘violation of FOREIGN KEY constraint “AVAIL_FUNDS”.

On the backend, EMPLOYEE Table is linked to ASSETS by employee id; cascade update and cascade delete.
All other tables -- including AVAIL_FUNDS -- where the employee ids are linked, are cascade update and set null on delete.
Calling “DELETE” only, on the employee table from either the backend or the front end operates properly. All linked records in ASSETS are deleted and the other tables set the associated records value to NULL.
Running the code will insert the values into the FUNDS and BUYO datasets, and will post/commit the values in the database, then return the error on DELETE of the employee.
One thing I’ve noticed, after commit the Employee dataset (EmpDS) is not closing as expected. For some reason it remain in the “Active” state.
Any assistance would be greatly appreciated.

Front end: C++ Builder 6 Pro (build 10.166)
Backend: Interbase 7.5 ; Dialect 3
Win XP ; Service Pack 2

void __fastcall TEmployeeFrm::btnBuyoutClick(TObject *Sender)
{
  int shBuyOut = DataMod->EmpDS->FieldByName("EMPLOYEEID")->AsInteger;
  AnsiString currName =  DataMod->EmpDS->FieldByName("FULL_NAME")->AsString;

  Variant cpStanding = DataMod->StandDS->Lookup("EMPLOYEE",shBuyOut,"SUM_OF_ADDEDASSET1");

  DataMod->FundsDS->Last();

  double currAvail = DataMod->FundsDS->FieldByName("CURR_FUNDS")->AsCurrency,
         shStanding = cpStanding,
         payAmount = 0,
         curr_money_change = 0;

  payAmount = shStanding * currAvail;
  curr_money_change = currAvail - payAmount;

  DataMod->FundsDS->Insert();
  DataMod->FundsDS->FieldByName("CURR_FUNDS")->AsCurrency = curr_money_change;
  DataMod->FundsDS->FieldByName("EMP_ID")->AsInteger = shBuyOut;
  DataMod->FundsDS->FieldByName("CHANGE")->AsCurrency = payAmount;
  DataMod->FundsDS->FieldByName("AVAIL_BY")->AsString = currName;

  DataMod->FundsDS->Post();

  if(DataMod->FundsTA->Active == false)
    DataMod->FundsTA->StartTransaction();

  Screen->Cursor = crSQLWait;

  DataMod->EmpDS->DisableControls();
  try
  {
    DataMod->FundsTA->Commit();
  }
  __finally
  {
    for(int z=0; z < DataMod->Corporate->DataSetCount; z++)
      DataMod->Corporate->DataSets[z]->Active = true;
  }

  DataMod->BuyODS->Insert();
  DataMod->BuyODS->FieldByName("EMPLOY_ID")->AsInteger = shBuyOut;
  DataMod->BuyODS->FieldByName("BO_NAME")->AsString = currName;
  DataMod->BuyODS->FieldByName("BO_STANDING")->AsCurrency = shStanding;
  DataMod->BuyODS->FieldByName("BO_CURR_FUNDS")->AsCurrency = currAvail;
  DataMod->BuyODS->FieldByName("PAYOUT")->AsCurrency = payAmount;


  DataMod->BuyODS->Post();

  if(DataMod->BuyOTA->Active == false)
    DataMod->BuyOTA->StartTransaction();

  try
  {
    DataMod->BuyOTA->Commit();
  }
  __finally
  {
    for(int y=0; y < DataMod->Corporate->DataSetCount; y++)
      DataMod->Corporate->DataSets[y]->Active = true;
    DataMod->EmpDS->EnableControls();
  }

  TLocateOptions SearchEmp;
  SearchEmp.Clear();
  bool FoundEmp = DataMod->EmpDS->Locate("EMPLOYEEID", shBuyOut, SearchEmp);
  if(FoundEmp == true)
    DataMod->EmpDS->Delete();

  if(DataMod->EmpTA->Active == false)
    DataMod->EmpTA->StartTransaction();

  try
  {
    DataMod->EmpTA->Commit();
  }
  __finally
  {
    for(int x=0; x < DataMod->Corporate->DataSetCount; x++)
      DataMod->Corporate->DataSets[x]->Active = true;
    DataMod->EmpDS->EnableControls();
  }
  Screen->Cursor = crDefault;
}