Attempting photo hosting

What is it with blogger being so extremely picky about where/how/why your profile photo is hosted? When I finally found a host for my first picture under the 68 character minimum it was fine, but now I want to update, and can't load the page for the first host, so I tried a new one, and even though the URL came in under 68 characters and the file size was fine blogger wouldn't let me save changes, saying that my photo didn't have "an acceptable extension" (eg .jpg). My arse it didn't...