Unexpected results from forcing the ChangeTo

I've got a worker function which having completed an insert does the
following:

//to get the id of the field, requery the database with the @@IDENTITY
string

_variant_t vNull;
vNull.vt = VT_ERROR;
vNull.scode = DISP_E_PARAMNOTFOUND;

// having done the insert...

_bstr_t bstrQuery("SELECT @@IDENTITY");

//create a recordset to hold the queried data which is the identity
adoRS->Open(_variant_t(bstrQuery), vNull ,
   ADODB::adOpenStatic, ADODB::adLockBatchOptimistic,
ADODB::adCmdText );

_variant_t vID;
vID = adoRS->GetCollect(L"");

//vID.ChangeType(VT_I4); // hangs here
*lPrimaryKey = vID.lVal;

//close the recordset
adoRS->Close();


Now given the schema of some of my database tables, it seems I don't always
expect, in this worker, to get a valid vID.lVal back - if I actually call
ChangeTo on the vID.lVal, against SQLServer2000SP3, the com+ server hangs,
the database has outstanding locks, and eventually the (scripting) clients
time out, or if I shutdown the calling object, the system sorts itself out.

Now these #imported calls are inside a try catch which I'd have expected to
fire, seems it doesn't .. if I put a simple local catch all around the
vID.ChangeType(VT_I4) then I get to continue without hanging.

Now I appreciate that ChangeType might be failing based on the actual table
that the generic function as called to act against, but I'm loathe to
remove the explicit coersion...

Arp

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