i dun have much experience in shooting the moon," well apart from in hearts"=O, but this is wat i feel:
from your picture, we can see that the moon have start to turn 'oval' this is due to long exposure which capture the movement of the moon itself (yes, the moon moves much faster then we though).
also my personal opinion is tat you got it over expose. try lowering your shutter speed, say by abt 3 stops. in cam metering would gives you a much over exposure reading due to the vast amt of dark sky ard it.
set to manual put your aperature to widest, which i believe is F2.8 for your 5050 at tele and 1.8 at wide(correct me if i am wrong).then bracket with vary shutter speed tll you get a ritz exposure.
double exposure means shooting 2 times on a single frame of a slide.
first exposure: shoot at cityscape making sure a corner of the sky is pitch dark where you wanna place the moon
2nd exposure: zoom in shoot at the moon at the area where you have plan it to be.
do give it a few tries, if still cannot post us the setting you have. we will try to help =p
there is a lot of light pollution in singapore. meaning the parts of the sky that is supposed to be black is not black...so exposing long will result in a colouration on the sky that i do not find desirable. i would spot meter the mooon... and open up a few stops... and bracket. to get the moon in the correct tone you want it to be...
experiment with you digital cam... dunno if the 5050 has spot meter though
I got quite a nice full moon with my SLR b4. I haven scan it yet.
But from my experience, using Aperture piority, (I can only open up to F5.6 with my 300mm lens) Try to point to the centre of the moon. So that the camera will detect it as kind of bright, it will increase the shutter speed. Mine was btw 1/125-1/350 depending on which "spot" on the moon that I point, near the crater (where there are slightly darker parts)
At F5.6, 1/125, the moon appear ok without the halo, but the crater wasnt very clear...seems a bit washed out.
At F5.6, 1/350, the moon appear to have more defined craters. (The "rabbit" shape looks more defined)
So I suppose u play around this setting bah? Then ownself alter alter a bit...see which settings u prefer
By the way, I shoot my moon handheld. Cos...ermmm I think 1/350 is ok to handheld bah?