Problem with Netgear WPN111 Wireless USB adaptor.

Any1 here having problems with the WPN111?
I have 3 computers connected up to a wireless network, and they all seem to
experience the same problem in that after a while, although the icon shows
that they r still connected and receiving a signal, they can no longer
connect to the wireless router which is a Netgear model. By this I mean they
can no longer connect to the Internet, and when I do a scan, they can't see
ANY wireless network, including my own. So I have to disconnect/reconnect
the device, and then it works again. I am using Windows 98 on all the
machines, so maybe the driver doesn't work too good with this operating
system?

There is also the problem that when I use WEP, I have to manually enter a
64bit key, because it doesn't seem to work when I use a passphrase keyword.
I got someone to verify this on another wireless router, and they had the
same problem as well.

Any comments would be greatfully appreciated.