I was watching The Daily Show today and noticed that Laura Kightlinger, the Daily Show's new corrsepondent, sounded a little bit like Sandi (and her mother). While listening to her voice in that piece (about the image of Bozo the Clown apearing in the stained-glass window of a church) I could hear that it would be very easy for her to slip into a Sandi-ish voice. Is it possible that Lisa Collins is a pseudonym used by Kightlinger?
Normally I would have thought nothing of it, but.... Laura Kightlinger co-wrote "This Year's Model." She obviously knows Glenn Eichler and probably most of the staff.
The Daily Show is taped in New York. Daria is produced in New York. I assume she would live in New York to do the gig for the Daily, that would make it easy for her to go to the Daria studios and do whatever Sandi voices needed to be done. now, this is where the first hole for this theory could be, she is a writer for Dennis Miller's show on HBO. Is Dennis Miller done in LA or New York?
There is some speculation that Nora Laudini is a pseudonym used by Nora Dunn (from SNL and recently appeared in episodes of Everbody Loves Raymond and The X-Files)
Finally, There are some folks (you know who you are) who claim that Tracy Grandstaff is really Janeane Garofalo. This theory is false but it deserves to be acknowledged whenever possible.
Anyway it's just a theory, please feel free to confirm, deny, or flame it.