[Dog Star (Phil)]

Tuesday night (16/12/08) I had the dob out for a bit of a waltz and was generally enjoying myself.
Was admiring 47 Tucanae (as I often do) with a 15mm ep in my 12" 1500 mm dob giving a 100x view at about 10:30 pm CST.
As I was looking at it I noticed a VERY faint (not experienced enough to give a magnitude rating, but it was BLOODY faint) object passing from roughly ESE - WSW. Tracked it for maybe 15-20 degrees until I lost sight of it.
It moved at roughly the same speed as a sattelite, which is what I assumed it was, although maybe a very small one, maybe even just a bit of debris.
Thinking about it the next day however, I couldn't understand how I could be seeing a sattelite at 10:30 at night given that the Sun had set around 7:50. What was illuminating it?
It wasn't a meteor (didn't break up or flare), it wasn't a comet (moving too fast and was just a single point of light).
There my speculation ends.
I'm still thinking that it was a bit of space debris but I don't understand how I was able to observe it, if that is what it really was.
I've been thinking about it ever since and I'm damned if I can explain it with my limited understanding.
I'm sure that there is a simple explaination for it, but my simple mind can't come up with the goods.
Can anyone help?