Comment 10 for bug 572772

Same issue here, using amd64 architecture, but I seem to have got it working.
Went to konsole and ran sudo firefox
I was able to save images while running in this mode though the console output showed the above errors regarding io-slave. Also the graphics of the browser itself seemed to go into a blocky "safe mode" of sorts. I closed firefox and logged out, logged back in and ran firefox as usual (no sudo priviledges) and saving images seems to be working for me now.

Hope this helps track down the bug