I have a delphi app with odbc/bde connection to the oracle 9i DB. The servers operating system it´s windows2000 Terminal Server. Sometimes I have seen that the thousans separators in the database show like this "10,000" and sometimes like this "10.000"
Other parameters that may be changed by the user session are the monetary paramaters that drive the currency and punctuation symbols: NLS_CURRENCY, NLS_ISO_CURRENCY, NLS_MONETARY_CHARACTERS which are driven by the 'TERRITORY' setting ing NLS_LANG or by default in NLS_TERRITORY.
You may want to check these settings in the database to compare against the setting of NLS_LANG in the clients.