AR cheats problem on TTDS

Hey there,

I've ran into a bit of a strange problem with a TTDS. The other day AR cheats were working just fine on pkmn plat ver. and now they don't, same thing goes for contra 4. all the other games' cheats are working fine, but not these two. especially wierd since plat cheats were working before. After switching cheats to ON and applying cheats then hitting SAVE, the little yellow key is on indicating cheats are active, but when i go back into the cheat selection page, the boxes are all unchecked. Does anyone know of this kind of problem, is it specific to TTDS's? The cheats just don't seem to activate for these two games now, but were before. I am really up the creek on this one, i've read around but there's nothing on it.

thanks in advance.

EDIT: Problem solved. The TTDS writes to the card in capital/upper case letters for Contra 4, and the TTDS can't seem to link Contra 4.nds with the CONTRA 4.ARP file, creating a new ARP file everytime for a game that it couldn't recognise, there was about 8 of them. I simply renamed the cheat file in lower case, but changing the rom name to upper case does the job too. ie. Contra 4.ARP, the ARP extension can remain upper case, just like any other game.
Cheers