To report a bug please be sure your issue is o-blog related.

You can bootstrap a simple clean environment

rm -rf ~/dev/.emacs.d
mkdir -p ~/dev/.emacs.d
cd ~/dev/.emacs.d
git clone git://github.com/renard/o-blog.git
git clone git://orgmode.org/org-mode.git

Then launch emacs:

cd ~/dev
rm -rf .emacs.d/o-blog/example/out
emacs --debug-init -Q  -l .emacs.d/o-blog/sample-init.el --eval \
    '(progn (setq browse-url-generic-program "x-www-browser"
      browse-url-browser-function (quote browse-url-generic))
      (ob-build-sample))'

You can change x-www-browser to your favorite browser.

If anything runs fine emacs would exit normally. Otherwise a buffer called o-blog Bug-report is created and its content is copied to primary X selection (if available). This buffer contains useful information for debugging your issue. A browser is launch to the o-blog new issue page. You can either paste content of the o-blog Bug-report buffer or the X primary selection (middle click).

Please describe as much as possible your issue (in English). do no hesitate to paste your blog file to https://gist.github.com/ this might be useful to debug.