I know it's a bit late, but the imgur Chrome extension allows you to right-click and rehost any image file. If you are logged into imgur, it will be associated with your imgur account. Otherwise, it will be anonymous. This can be done from any site, including imgur.com.
Safe to say there's a problem : http://www.isitdownrightnow.com/imgur.com.html
It's slow whether I use RES or go to the actual Imgur page. For info I'm in France too, on Free, but I don't think it's ISP related, given the isitdownrightnow.com results.
OAuth is very picky - I would use a library from http://oauth.net/code/ if you aren't already.
In my case, I adapted the code from this blog post: It extends the oAuthBase.cs code from the above link.
http://www.voiceoftech.com/swhitley/index.php/2010/02/twitter-oauth-with-net-for-the-desktop/