Accessing vista shares with Windows 98SE

I have a couple old computers in my home running Windows 98SE. I normally
share an entire storage drive in my main computer so that stuff like music
and video can easily be accessed by all computers. Under Windows XP, the 98
machines can access files perfectly. However, if the drive is shared under
Vista the 98 machines experience severe problems reading the files. The
folder list takes roughly 30-60 seconds to appear, and initially appears
incomplete. Only some of the folders are listed, and folders like 'My Music'
only appear as 'My'. What's even more interesting is if I go into one of the
folders, I can browse those files at normal speed and without any weird
problems. If I try to make changes to those files, once again it slows down
and virtually locks up the 98 machines. I have not tried playing with this
yet, but could IPv6 be causing this type of problem? Currently both IPv6 and
IPv4 are enabled in Vista. Even google fails to return relevant help here.