Importing QIF: Name Conflict with another account

[marchaljn at yahoo.com]

I am importing QIF data from a Calc spreadsheet with the Calc2Qif wizard   Everything seems to be working fine except that I can't find a way to get the information mapped to the existing accounts. Duplicate accounts are created and I get the message: 'QIF import: Name Conflict with another account'.
I have seen this problem described several times.  The typical explanation is that the account type or currency don't match.
However, I have carefully set the correct account type in Calc2Qif (Investment), and set the currency (US dollar) at the end of the import process.  I have checked that the Gnucash accounts are indeed 'Investment' and in US dollars.  Also, during the Calc2Qif process, the wizard seems to accept the existing accounts (the box for new account is not checked).
After many attempts and verifications, I still get the same result: duplicate accounts created and same message.
Can anybody help?
Thanks a lot.