row literal problem

I'm chasing up an issue from a client who has this problem (in 9.1):

with q as
(
some query here
)
select q.* from q

yields:

job_scope | checked_col
-----------------------------------------------+------------------------------------------
Co Revenues: Co Revenues $100 to $999 Million | <input panel=data
type=checkbox checked>
Metropolitan Area: Austin-Round Rock | <input panel=data
type=checkbox checked>

which is as expected.

However,

with q as
(
same query here
)
select q from q

yields:

q
-----------------------------------------------------------------------------------------------
("Co Revenues: Co Revenues $100 to $999 Million","<input panel=data
type=checkbox checked>",)
("Metropolitan Area: Austin-Round Rock","<input panel=data
type=checkbox checked>",)

Note the trailing comma inside the (), which certainly looks bogus to
me. If I replace "select q" with "select row(q.*)" it disappears.

It doesn't happen in all cases, and I'm trying to work out a minimal
reproducible example. But it sure is puzzling.

cheers

andrew