Max size of dBASE DBT (memo) file???

What is the MAXIMUM size of a dBASE DBT (memo) file?

I have an application that has a DBT file approaching two gigabytes on a
WinNT server used by two workstations.  All of a sudden I've started to get
an error that says that it's unable to Save a new record to the table
because of an error in the DBT file (unable to read).  But, all existing
records work fine...

I have written a delphi program to iterate through the entire table and I
used the SaveToStream on all ftMemo and ftDBASEOle fields using the
pseudocode below:

try
    ms := TMemoryStream.create;
    first;
    while not eof do begin
        for i := 0 to fieldCount-1 do begin
            if fields[i].dataType in [ftMemo,ftDbaseOLE] then begin
                ms.clear;
                TBlobField(fields[i]).saveToStream(ms);
                end;
            end;
        next;
        end;

    ms.free;
except
    report error
    end;

I've not identified any errors using this logic, so I wondered if it's
something else that might be going on.  I've tried reindexing the table, but
that doesn't seem to help...

Can anyone help????

Thanks!