I never had a a problem with Flickr's batch upload program until Phil told me he had problems with it several months ago. Since then, every time I use it it craps out on me half way through uploading a batch.
Then, at lunch on Friday, Phil mentioned to me that whenever he uses Yahoo mail (which is rare) he gets a slow-load error. I told Phil that he had just jinxed my Yahoo mail experience and I was soon going to get similar errors.
I was right.