How to use ADO to insert BYTEA data?

I try to write this code for postgresql (for mysql working fine):

try
{
m_pRecordset->AddNew();
iTimes++;

VARIANT bitdata[3];

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

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]);
}

When calling AppendChunk error occurs.
Please help me, thks!

peng