one is encrypted one isn't they both work on the r4 and both of them do not need to be present to get cheats working.
http://gbatemp.net/index.php?showtopic=84991
To R4DS Users:
To R4 users and its clones, use either CHEAT.dat or USRCHEAT.dat and not both, using both will cause some codes and games not to show up.
For those having problems with some games not showing up like Yu-Gi-Oh its due to a bug/limit in your flashcart (R4, M3 Simply, ect) and you have a few options.
Plese check out this notice for more information on how to fix this problem:
http://cheats.gbatemp.net/#notice
Note:
An update tonight folks! Sorry for the late post, I ended up uploading the update hours ago but ended up dozing off before I can make a post about it. Also if you find nay codes, please post them or link them here, thanks.
For R4DS users and its clones
The R4DS contains a flaw that prevents some cheats from working on it. Though luckily there is a fix! Thanks to Yasu, the creator of R4CCE, there is a patch for the R4DS kernel that makes the cheats work. The program is called r4bugfix2 and you can get it on Yasu's English software page here. Its easy enough to use, all you have to do is simply drop your _DS_MENU.DAT file from the R4 kernel on the r4bugfix.exe program. and it will patch it. Alternately, you can copy the file to the same folder as the r4bugfix file and click the execute. Afterwards, place the patched _DS_MENU.DAT file on your flashcart. Also, as with updating your firmware, I suggest deleting the _DS_MENU.SYS file and allow the R4DS to recreate it to prevent problems.
Note: You can find the pre-patched _DS_MENU.DAT file
here for the R4DS 1.18 kernel.
-another world