How long were the exposures Pat ? My guess would be they are hot pixels which the camera has detected and tried to cover with a hot pixel algorithm. The result has been a darker spot than intend because the algorithm is designed to work on night shots where it covers the hot pixel with a dark spot which blends in with the dark sky.

Message edited on: 07/22/2005 14:10

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html