Linksys WAG345G & Nintendo DS

Hi, new to all this WiFi fandangle as I use wired LAN mostly but with the advent of Xbox360 and Nontendo DS etc I find the need to activate my wireless connection. I was wondering if anyone has had any experience with setting up a DS and getting it to work on their router?

I have 3 DS's in the house 1xUS, 1xUK & 1x UK DS-Lite. I can set them up to connec to to the router and they get as far as obtaining an IP adress and fail. This is using 64bit WEP as the DS's dont support WPA. they cant seem to obtain an IP address. I have enabled & Disabled MAC filtering to allow them access etc. even opened up wireless completely with almost no security to no avail. Even my 360 has issues with WEP. With WPA, all is fine, 360 has no probs but DS does nto support this.

Anyone able to offer any insight. Any help is appreciated.