First you claim they're routers, then you claim they're transparent. Those are pretty much mutually exclusive statements, so I'm not quite sure what's going on.

If they're routers, they have to be configured in the host computer as routers, either as the default router or as a static route to another specfic set of networks. Not knowing how your network is set up otherwise I don't know exactly what to tell you other than to compare the routing tables between the new machine and the ones that are working. (Under Windows, this is "route print" from a command prompt.)

If they're transparent, that probably means that they're bridges. I can't think of anything obvious, but they might have some sort of MAC address filtering. Did you or the people your work with set up the currently working computers after the bridge was put in place? If not, can you find the person who did set them up or ther person who installed the bridges and ask if any special configuration was needed on them?