I think the mistake you are making is in uploading images one at a time. By far the best way is to go to images, upload, and use the drag & drop uploader. Have your image file open, then click on restore in auctiva (the button next to the x at the top of your screen).
All you have to do is point to an image, hold down the left mouse button, drag the picture into the uplod space, then release.
You can upload up to 100 images at a time, but to make your life easier later on, it's worth setting up some folders first.
I sell a lot of Greetings Cards, so I have folders called Mother's Day, Birthday, Valentine's Day, etc.
Once you've selected the images you want to upload, select a folder, and click on Upload.