Can't get table list from C/ODBC

I have a problem with getting data from Navision into Excel via C/ODBC. During Data Import operation Excel says “Unable to get the list of tables” (or something like this). I have Navision Attain 3.70; user name has SUPER role; in License information there is Qty=1 for C/ODBC. Navision uses native DB. C/ODBC is on the same server and Navision (I access it via “localhost” server name - transport is TCP). What might be wrong? Thanks in advance.