Thanks for replying.
I have looked into SQL-relay before, but it doesn't quite solve our problem. One of the reasons that we are using DBI proxy is to get away from FreeTDS. DBI proxy allows the use of ODBC to connect to SQL server, which seems to work better. I know it is possible to do ODBC from Linux, but from the research I have done it looks like it would be rather involved to setup and I haven't found a free ODBC driver for Linux. That's why I was hoping that there was a known fix to DBI proxy.
Thanks for your suggestion.