Gouken,
It does seem like there is an error regarding an Arial font not being embedded. Did you check the option in the Image Job Options tab to embed all the fonts? Did you also configure the services with proper admin rights, which might otherwise prevent them from accessing the Windows fonts folder? And of course, make sure the font is available and isn't read-only. (would be surprising, this being Arial, which is a very common font, but you never know...)
I'd start with that, let us know how it goes!
Regards,
Raphaël Lalonde Lefebvre