I had same issue...
with windows it's easy to mount PC HDD to my vuDuo but when move to mac osx i tried many methods with NO success :-(
BUT there is a solution i founded it, If you like me want to watch videos from your mac into vu+ use this method:-
my advice do not use CIFS,AFP or SMB try to use DLNA... How? see...
1- there is many APPs to make you mac as DLNA server and i almost tried them all the best one for me is "
PlayBack" it's easy and smarter
2- in your vu+ download plugin "DLNA browser"
or if you have a TV that DLNA support also will work
that's in sort word, if you want any help tell me please
best regards