can't access other network computer

i have 2 PC with win98se, and one accesspoint to connect
my 2 pc together using usb wireless adapter. let the 2 pc
be a PC A and PC B, when PC A and PC B share out a folder
and file, From PC A i try to access the PC B but the PC A
can't even see the PC B computer in the network
neighborhood and also if i use run, it show up a message
of unknow host! After that, i try to use ping to ping the
PC B but it successful with replied. But in the other way
round, i use PC B to connect PC A share folder and file,
in network neighborhood i can see the PC A and able to
access the folder, but while i open the folder that
contain file it take very long time finish load the file
and it not allow me to open the when i double click to
open it. what actually happen to my computer network? i
have not use any firewall for my PC and accesspoint and
TCP/IP setting is all done well which i use ping each
other can be successfully with replied, the only thing is
i can't access the network folder.... please help...