From what I read and tested here is really the fault of the windows, because who does not list the network machine is not done by windows wd hd.
I noticed this because the own network between windows xp is not seeing the windows 7 but IP was good.
I saw also that this problem happens between two network windows 7, because of the **bleep** password it generated when the master browser fails to list the pcs really wd hd will fail.
But I think the wd could create a host list as in linux i solve the problem, now depend on hehehehehe microsoft is a joke right!
