TBH I had no end of trouble trying to get MiamiDx working with a similar setup, i.e. PCMCIA card in Hydra housing to Win98 (at the time), it didn't like initialising the hydrapcm.device, there were problems when trying to use cnet.device in AND out of the Hydra housing because of blah blah blah blah....
I then tried Genesis w/ OS3.9, set up all the same details and it just worked.