I am tweaking TwentyTen and stumbled on a problem..
It seems that when inserting left-aligned pictures in pages WP adds: style="width: 650px" to the image which means an extra 10 px to the image's actual width. It doesn't show in html-mode either as it does if you add margin in the advanced preferences for the image.
Since it gets created directly in the page I can't take it away in the style-sheet. It doesn't make a change either to use negative margins in the style-sheet.
The result creates a 10px space to the left of the picture.
Where is it initiated? Any WP-guru out there to help?