Truemobile 1300 vs Netgear WG602 AP on XPPro

This combo has a few 'features' that I would like to eradicate. Setup is
XPPro on a Latitude D600. XP SP1 installed, Wireless Rollup package
installed on top of a few other mandatory security patches. Wireless AP
has latest firmware installed (1.5.67). Truemobile 1300 (hardware rev
4.5) has latest driver 3.20.23.0 from Dell.
XP's wireless management is disabled - card and network setup is done
through the "Dell Wireless Config Utility" in control panel. network is
set to use DHCP server which is a Netgear RT328 ISDN router which is
accessed via the WAP. The WAP obtains its own IP address from the router.
No encryption is setup on the WAP or on the network card - this will be
the next step but I reckoned that it would be one less thing to sort out
until I get a reliable connection.
The following features remain after
a) Connecting to network resources (shares and printers on Win98SE
workgroup computers) almost never works first time. \\x\y is not
accessible. You might not have permission... Network path not found
b) Connections drop out. There are no interfering radio sources (no
microwave ovens operating, no mobile phones operating no wireless alarms
in same frequency band, no neighbours with similar equipment) as far as
I can see.
c) System reassigns incompatible IP address (different netmask etc) when
system resumes from hibernation or system standby.
'Repairing' the network connection (is this the same as ipconfig
/renew?) doesn't seem to work.
I have just switched the laptop from DHCP to static IP but this doesn't
seem to have resolved anything. Just got two failed attempts to connect
to shared drive before it worked at third attempt. (Laptop is 1m from
WAP, signal strength is excellent -30dBm vs noise at -85 dBm. and speed
is showing as 54mbps)

Has anyone got any suggestions?