If you don't want to know the circumstances surrounding Wedneday's entry in this slideshow, then don't read any further...
[spoiler]Wednesday's quote:
Ep #1077 (1970) - Quentin - 'Well, I MUST say that your gratitude is less than overwhelming.'
From "#1076/1077: Robservations - 08/22/03: Quentin Besotted"
Quentin knocks at David's door, making Daphne disappear. Quentin has brought his camera, which David wanted to borrow for the picnic (another clue!). Thank you, says David. i must say your gratitude is less than overwhelming, says Q, you've been wanting to use my camera for the last year, and now...Quentin stops. David, he says, I'd swear that I smelled lilacs. It's too late for them to bloom, says David. I know that, says Quentin
The Robservations references the quote almost perfectly...
And this is the second quote from this ep. The first (Quentin - 'You MUST have led me here for a reason-- if you need help, there's nothing I won't do, but you MUST appear to me') was back on February 16th.