ADSL Line Provider: NTT using ADSL Modem NVIII
ADSL Service: commercial JENS ADSL Service (Japan Telecom) with fixed
IP address, PPPoE
Router: Linksys WRT54GS-JP (same as WRT54G but w/ Japanese menus)
PCs: Mac Mini, Powerbook (both OS X)

ADSL Modem configured and connecting.  Directly connecting mac mini to
ADSL modem results in problem free internet connection, with proper
connections and DNS name resolutions.  Problems when placing Linksys
WRT54G between PCs and Linksys router.  Using PPPoE setup on Linksys,
can get connection.  On admin screen for router, see that correct
global IP address, DNS servers being obtained from ADSL modem.  On PC
side, can ping specific IP addresses, however cannot ping DNS servers
or get name resolution.  Have tried setting up router w/ same MAC
address as PC, changing the local network address space to 192.167.x.x
(based on doc that some ADSL servers not working properly with
192.168.x.x space, etc.

As have global IP address, have of course also tried setting up router
using fixed IP parameters:

IP address: aaa.bbb.128.33
Subnet: tried 255.255.255.255, 255.255.255.0, 255.255.0.0
Default Gateway: xxx.yyy.1.141 (value returned when using PPPoE)
DNS1: xxx.yyy.16.2
DNS2: xxx.yyy.8.2

Each of the settings were rejected at the point of submission,
255.255.255.255 for being invalid, and the others for the gateway and
IP not matching.

I would like assistance in resolving this issue.

Have you tried checking the transparent bridge box in your linksys
WRT54G .. If your linksys is only their for wireless access and doesnt
perform any DHCP or NAT then I think you should try that.. TRANSPARENT
BRIDGE