Using VC2008 to store bytea, I got AppendChunk error 800a0c93

My server is pg 9.1.13 in win8 64, my client is win xp 32 bit
installed psqlodbc_09_01_0200.zip（ide is VS2008, vc++）.
When I store pic binary data to bytea (field is CapturePic) using:
try
{
m_pRecordset->AddNew();
iTimes++;

VARIANT bitdata[3];

SAFEARRAY *psafe[3] = {NULL, NULL, NULL};
SAFEARRAYBOUND band[3];

if (pFreImg != NULL && FreImgSize > 0)
{
bitdata[0].vt = VT_ARRAY | VT_UI1;
band[0].cElements = FreImgSize;
band[0].lLbound = 0;
psafe[0] = SafeArrayCreate(VT_UI1, 1, &band[0]);

for (long iSize = 0; iSize < FreImgSize; iSize++)
{
SafeArrayPutElement(psafe[0], &iSize, &pFreImg[iSize]);
}

bitdata[0].parray = psafe[0];
if (bitdata[0].parray != NULL)
{
m_pRecordset->GetFields()->GetItem("CapturePic")->AppendChunk(&bitdata[0]);
}
...
m_pRecordset->Update();
...
}catch()

I got com_error (at line ...>AppendChunk() ),and see in AppendChunk():
HRESULT _hr = raw_AppendChunk(data);
I got: hresult 800a0c93

see http://tutorials.aspfaq.com/8000xxxxx-errors/why-do-i-get-800a0c93-errors.html

how to resolve it?