I've been trying in vain to upload a video to post here, but I can't get past YouTube's "Upload as..." dialog box because it won't allow me to enter my name, and all attempts to upload to Vimeo - I've converted my m4v to avi, flv, mov, mp4, mpg, and wmv. - have failed.

I've disabled extensions,enabled all cookies, and tried in both Safari and Firefox with no joy.

Has anybody got any suggestions?

Thanks.