If you have trouble uploading your photos, you can try changing the upload mechanism.
On the 'Upload' page, click on 'Advanced Options'. In the drop-down menu, select 'Basic Uploader'. The basic uploader allows you to upload only one photo at a time. Click on 'Add Photo' to upload each photo. Continue the uploading process.
To switch back to the batch uploader (which allows you to upload multiple photos at once), click on 'Advanced Options', and select 'Batch Uploader (Flash 8)' in the drop-down menu.