TwentyTen 3.0.5 Image Resizing not working

IMAGE RE-SIZING HELP REQUEST

I have a TwentyTen theme WordPress-based photography website:

cassidyphotography.net

I uploaded the TwentyTen theme and have been working with it, since February 1st. It is very frustrating at times. Just when I think I have got it figured out . . .

If you go to Portfolio > Modeling you will also note there are photos of different sizes.

There is just no damned way I can make them one size. It seems whatever way I attack the photo or image size, they show larger or smaller on the WordPress Dashboard, but after I Update, nothing has been changed. I have tried using Apple iMac and Safari OS X. I have
tried Windows XP and Firefox. Oddly sometimes they load to Media and other times to Gallery . . . I have not figured this out, yet, either.

I have a Page Titled: Screen Calibration Check . . . it was a Test Image that I created to play with in TwentyTen. I ended up modifying the style.css to get what you see. I thought myself clever, until I tried uploading smaller photos of Models and resizing them . . .

When I upload the photos, I am sure to make them 671px X 446px, for example, but they come out different sizes, in practice, on my website.

I wrote to many different folks about the situation including my Website Host and to the Author of TwentyTen, a few times, actually . . . No reply.

I would need to know precisely what file to change or where to make changes in style.css.

Can anyone advise?

[Email address removed]