Hi Roy, I'm not sure about those times. 22:00 UTC is 8am & 23:23 is 9:23am, if you're in Sydney.

C/2010 X1 is certainly moving through that field at the moment, but very slowly. The movement in less than an hour and a half at that scale would barely be noticeable (around 10 arcseconds, or less than the distance between the pair of dim stars immediately to the right of the first marked dot).
On spec, I ran X1's ephemeris position for 10pm (22:00 EST) and your second shot shows a brownish dot in roughly the right position but there is no sign of it in the first pic (and nothing shows there in DSS plates).
I ran a 15-arcmin radius of the comet's position through the MP checker for 10pm and the only result was a mag 19.1 asteroid (mp), 2000 CD83, which was nowhere near the action and too dim anyway. The second marked dot you have looks very purplish to me, like a hot pixel, but I'm assuming you have a set of subs that show it moving, and these two subs are the end-points.
The left-hand of the pair of dim stars to the right of the object marked in the first pic is V-mag 16.64 so you're going quite deep. I can't understand why X1 isn't a reasonably bright object with a short tail in your shot, at ~mag 14. Unless I'm not picking it up.
Anyway, if you can sort out the time we might get a better handle on what is or isn't there. Good stuff!
Cheers -