Round Robbin' by The Crossword Centre

Subsidiary indications in seven across and seven down clues fail to account for something; in each remaining across clue subsidiary indication and its entry are similarly lacking whereas nothing is missing from the remaining down clues and entries. Five answers are of two words. Definitions are reliable throughout and nothing needs to be highlighted.

    1    Tomb’s situation alongside banks of Euphrates (5)
    4    Attach blame to land for embracing system of electoral reform (8)
    9    Exchange 50% of presents in sale: what the hard up may do at Christmas? (9)
    11    Advance leaving women panicking corporal? (5)
    12    My old man and that woman are intertwined (6)
    13    Man is head-over-heels, captivated by queen's colonial charm (6)
    14    Half of downpour taken by the hollowed-out spout (5)
    15    New trees appearing after cutting separate ones from gardens – watch out! (12)
    18    Palaeontologist's first period encompassing Iroquois' principal tribesmen (6)
    19    State caused by a stunner that’s not half ravishing once (6)
    23    Bird with inclination to go after fashionable prince (12)
    24    A blue ass fly's last to enter Mr McKenna's sixth on Derek's centre (6)
    27    Bird's egg regurgitated before half of meal (7)
    28    Strike partner scoring sixth of season - justice for Roma (7)
    29    Occasionally recondite unknown book of manuscripts (5)
    30    Ungulate caught in West Country ditch by Royal Society (10)
    31    A name for stuff my idiot sister makes up (8)
    32    Private soldier's shot gaining Military Medal for resistance (5)
    1    Enter Amiens in error - Marie exits to the sound of trumpets (6)
    2    Advise beautiful girl to seduce Rector (6)
    3    Conflict punished soldiers after experience down under (8)
    4    Once again rank energised bishop ahead of retrograde cardinal (7)
    5    Some women washed Connery's just now (4)
    6    Rogue trader taking afternoon tea in New Jersey (7)
    7    Belt doubles itself on tucking in (4)
    8    Umbrella doesn't close and half of it becomes vessel for holding water! (6)
    10    Prius, pulling out of Vauxhall Museum, crushed toe (9)
    11    It's fun, having wound incompletely sewn up?  God, no! (9)
    16    King, Queen: that's no trumps coming up again (8)
    17    Albert and Victoria not the first couple to crush? (7)
    18    It may be provided by tripe and bananas (7)
    20    Mammals born live almost immediately look about (6)
    21    Best thing is to fill across space with down letter (6)
    22    Everyone gay when hearts have left closet (6)
    25    Recurrent condition seen on surface of skin (4)
    26    Drunken luthier made this (& lit)! (4)
Grid by Paul McKenna, clues by Trevor Crowther, Shirley Curran, Mike Draper, Brian Dungate, Richard Foden, Roddy Forman, Raphael Goldblatt, Andrew Gillespie-Smith, Oli Grant, David Harry, Paul Henderson, John Hood, Margaret Irvine, Georgie Johnson, Chris Lancaster, Simon Long, Eddie Looby, Robert Lorimer, Mike Lunan, Dean Mayer, Kevin McDermid, Stephen Mulligan, John Nicholson, Mike Norris, Mark Oshin, Frank Pasterczyk, Rishikesh C G, Mark Sambell, Simon Shaw, Ian Simpson, Neil Talbott, Dave Tilley, John Tozer, Luciano Ward, Clive Weatherley, Keith Williams, and edited by Derek Harrison. To enter this competition, send your entry as an image or in list format with a description of the theme, to before the 8th September 2013. Please vote for your favourite clue and the clue-writer who receives the most votes will get a prize. The first correct entry drawn from the hat will receive a copy of one of the range of books which has been donated by Chambers.