Last year, the show claimed its highest ever opening audience of 1.8m - however this year's launch rates as its lowest ever.
Airing at 10pm, the sitcom was seen by 885k (3.8%) on Channel 4, before 151k (1%) watched on timeshift an hour later.
David Mitchell, who stars as Mark Corrigan in the sitcom, had already recently suggested that the programme's TV audience may decline, after expressing his dismay at the show's earlier premiere on Channel 4's online platform 4OD.
Following at 10.30pm, the premiere of Robert's Web - which sees the Peep Show star make a mockery of the online world - appealed to 747k (4.2%), and only 91k (0.9%) on +1.
Elsewhere in the hour, Law & Order: SVU gripped 918k (4.4%), while BBC Two's The Stephen K Amos Show entertained 533k (2.3%), and The Graham Norton Show put in 3.24m (19.9%) from 10.35pm.
Earlier at 9pm, the latest episode of imported US drama The Event mustered 810k (3.3%), comfortably beaten by The Mentalist which attracted 1.32m (5.3%) to Channel 5.
Meanwhile, Lembit Opik's exit from I'm A Celebrity... Get Me Out Of Here delivered a hefty 9.03m (37.3%) to ITV1 in the 9pm hour, before ITV2 spinoff show I'm A Celebrity... Get Me Out Of Here Now managed 703k (4.3%).
Once again though, the most popular multichannel programme went to Foyle's War on ITV3, which nabbed 947k (4.3%) between 9pm and 11pm.
Back on the main networks, repeats of QI and New Tricks took 4.05m (16.9%) and 4.11m (16.6%) for BBC One, while Gardeners' World and Britain By Bike logged 1.44m (5.9%) and 1.52m (6.2%) for BBC Two.
Prior to that, 2.55m (10.9%) watched Mastermind, Cheetah Kingdom snapped up 3.02m (13%), Come Dine With Me cooked up 1.63m (6.9%) for Channel 4 plus 200k (0.8%) on timeshift, and Channel 5's White Van Man fetched 642k (2.7%).
Overall in primetime, ITV1 eclipsed BBC One with a share of 32.2% to 20%, BBC Two claimed third place with 6.2%, and Channel 4 averaged 4.3% (+1: 0.6%), ahead of Channel 5's 3.4%.
BARB ratings data supplied by Attentional