Grrr, flippin' Flickr!

I decided today that, since Mark was woefully behind with uploading our photos to Flickr, I'd have a go at figuring out how to do it. By golly, it's so blinking easy I don't know how I failed to do it sooner. Of course, because we're just subscribed to the free account I didn't make much progress - I only got up to August last year - so, bizarrely, our 'most recent photos' are all almost a year old! Annoyingly, though, all the photos that Mark had previously uploaded have now disappeared, and even the first few I uploaded today aren't even in the archives. Any ideas why.....?