You can close this problem. It turns out that the problem was the "HTTPS Everywhere" Firefox addon. Upgrading to the latest version fixed it. Thanks. > From: Monica <http://www.stumbleupon.zendesk.com/~notifications-support> > Date: Thu, 18 Aug 2011 00:59:06 +0000 > > ## Please do not write below this line ## > > StumbleUpon Support Re: (#113968) share failed > > Your request (#113968) has been updated. > You can add a comment by replying to this email. > > ---------------------------------------------- > Monica, Aug-17 05:59 pm (PDT): > > Hello, > > Thank you for writing to us and reporting this issue. > > Our engineers and QA team have been notified and they are currently > investigating the issue. > > We will get back to you when we have more information. In the meantime, please > let us know if your issue has been fixed. If you have more data that will aid > us, please send it our way! > > Monica > StumbleUpon Support Team > > Be our friend on Facebook: https://www.facebook.com/StumbleUpon > Follow us on Twitter: http://twitter.com/#!/StumbleUpon > Read our blog: http://www.stumbleupon.com/sublog/ > ---------------------------------------------- > Chr3j7ekdb, Aug-11 06:10 am (PDT): > > Basically, we're having the same problem as reported in > http://getsatisfaction.com/stumbleupon/topics/share_failed > . > > I feel that it is a problem with stumbleupon.com and its servers and not the > browser or addon installation nor operating system nor anything on the client > side. > > P.S. I'm reporting this on behalf of "no.stumbleupon.com". > > -------------------------------- > This email is a service from StumbleUpon