TTable with Ascii file (TTAscii)

I'm using the TTable component, setting the tableType property to
ttAscii, to read a Text file with four fields, comma delimited, and
the first line containing the field names.

It is supposed to work just like that. But when I open it, it always
sees only one field. I've tried quoting the fields with "" and with
'', and unquoting the fields.

Does anyone know a way to fix it?
What am I doing wrong?