Strangness with uploading/maintaining User's Picture

Strange stuff there. Shortly after registering, I had no problem uploading a "picture", and it displayed fine on the site for about a day. Subsequently, after previously noted troubles with logging in, the picture has "vanished", and further attempts to upload a new one (Your Account-->Edit tab --< etc,) *seem* to work, but no picture is displayed after upload, or on pages.

Cleared caches, all the usual suspects...but no love..