How long are you waiting when you get your white screen.
Just as an experiment, just try one photo, click on upload, then go away and make a cup of tea, have a beer or mow the grass.
Come back half an hour later and see if anything has happened.
I'm wondering if there's a problem with the upload speed of your internet connection. Whilst you say you have an 8mb download speed, your upload speed is probably somewhere between 256 and 512k - probably somewhere in the 350k range. So while you may be able to download files nice and quickly, with Tiscali ADSL your 'upload' speed will be pathetically slow.
Regards
Graham