Another attempt on this one. Again G15 [D90], 4 x Luminance at 300 sec bin 2.
28 Mar 2009 12:21:48 - 12:39:43 UTC

You can just make it out on this stacked image


There are a couple of asteroids in the field, but at mag 20 proved too difficult to see in my images.
2005 CK20

and
2003 SG34

Yes....I have spotted it. Top left hand corner? Near the bright star (HD 104353). As yet unidentified SB. Follow up observations in progress.....