DS doens't recoginize R4 card in my sons DS Lite. My other sons DS does recoginize the R4 card. Why? how can I get the card to work in both DS Lites.

Yes, his games will work, as the DSi will be fully backwards compatible. You should be able to use the same memory card that he uses in the DS Lite.

The old R4 cards for the DS do not work in the DSi due to different firmware. You will need an R4DSi. Legal Disclaimer :- Please do not use R4 cards for playing illegaly downloaded computer games :)

I think you need to update the R4 software,dont know what is your R4 update website?
you know ,there are many version of r4, If you are in UK,i suggest you visit www.logictoyz.com

does it still work with original games if so you may need to update the firmware on the r4 card if not then take the ds back while its still in warrentry as there is no way they can tell what cartridge you've put in the slot1 part of the ds as all the firmware is on the sd card and never transfered to the ds

take it back, make sure the warrenty sticker is still on the bottom of the counsil, if not, contact NINTENDO, a phone number at NINTENDO.com

well some ds' insides are broken yours mightve been mistreated or the ds is just defective

hang about its even reckonising the card? let alone booting into the menu? sure you dont have a duff card? i had 2 of those, sent em back got replacements that work brill.

Me thinks you have the wrong R4 software installed on the chip....

I've done a few of these and all worked fine,,,, even a R4 III which was a tricky little number...... if it is the R4 III - i went for the older software and it worked,,,,, the new version failed on me.

I'll report back here in 30 mins....

this is a know issue with R4 clone cards, most R4 cards sold today are not real R4NDS cards because they have been discontinued
Most R4 clones have some trouble with firm version on DS make version and date.

You have to put the R4 v1.18 kernel on the memory card for it to work.
R4 web site is http://r4ds.cn/
In the download section is the r4 manual follow that and you should be ok.