The problem is very simple to exaplin.
A vanilla installation of mediawiki 1.0.17 + bluespice 1.0.1 works fine except for the displaing of the images.
I link two snapshot:
the wrong wiki page and the right rendering instead made by the the pdf print webservice extension.
Please contatc me at gbonazzoli AT bonaz.it if you want more information in order to fix the problem
Last but not least I think that you are doing very well with this initiative !!!!