Windows 9x PC will hang when access Vista share folder

Hi!;

Recently I just discover when windows 9x PC wants to access Windows Vista
share folder will facing problem. For example, when I use Windows 98 and want
to access Vista share folder and open certain files inside the share folder.
The Windows 98 system will direct hang and need to restart the PC. I have
tried few PC that running Windows 98 also faced the same problem. However if
I try to use Windows XP or Vista PC to access and open files from Vista share
folder, it is no problem. So may I know what the actual problem between Vista
and Windows 9x network?

Regards