You're rigt - it was dusk indeed :)
When it comes to sharpness - it is always hard to adjust the right amount of USM with such a small photo (it lacks all the details the larger version has). Besides - it looks completely different when seen on LCD and CRT (LCD's tend to be much sharper). On my screen it looks about right, but I believe it may be different on yours.
Thanks for your comment.
Spectacle of Light (64) *