Assuming your problem relates to wireless connectivity there must be a way of turning off the HH5 wirerless.
I factory reset the two expresses and then reconfigured the primary express that I have in another room (which is connected to the HH5 Gic Ethernet via homeplugs ) using the same wireless SSID and wireless key as the HH 5. I then extended the primary express signal using the 2nd express. All is working fine now and I have ONE network with 3 wireless routers (the HH and the 2 expresses).
All is good!
I am thinking of trying the same thing but I only have one airport express. Can I check that both of your airport expresses were the basic model. Did you use bridge mode or not?
use it in bridge mode and as stated above use consistent SSID's and passwords. Should work a treat.