SQLBrowseConnect: Invalid string or buffer length

Hello,

I am trying to get the SQLBrowseConnect function to work. I used
ODBCTest.exe from the MDAC SDK to check for results but I always get
messages like the following:

SQLBrowseConnect:
In: ConnectionHandle = 0x00761830,
InConnectionString =
"DSN=postgresql30", StringLength1 = 16, OutConnectionString = 0x000C8C18,
BufferLength = 300,
StringLength2Ptr = 0x000C2CD0
Return: SQL_ERROR=-1
Out: *OutConnectionString = <unmodified>,
*StringLength2Ptr = <unmodified>
dbc: szSqlState = "HY090", *pfNativeError = 0,
*pcbErrorMsg = 64
szErrorMsg = "[Microsoft][ODBC
Driver Manager] Invalid string or buffer length"

Input strings tried:
DSN=postgresql30
DSN=postgresql30;
Driver=PostgreSQL
Driver=PostgreSQL;
Driver={PostgreSQL}
Driver={PostgreSQL};

Where postgresql30 is a valid System DSN which I successfully use to
connect to the server with PGAdmin III
and PostgreSQL is the installed ODBC driver in version 7.03.01.00 . The
running backend is cygwin PostgreSQL 7.3.4.
The whole is running on Win2k with SP4 and MDAC 2.7 installed.

The ODBC 3 attribute has been set after acquiring the environment handle.
SQL_ATTR_ODBC_CURSORS=110 has been set to SQL_CUR_USE_ODBC=1 .

I would be really glad if someone had an idea what is wrong here.
Thanks in advance

Michele.