Yeah there is a way,
it took me like 15 minutes to figure out what was wrong.
Just make sure you have the 7-09-08 cheat file from Narin,
and then add the codes manually to one of the 7-09-08 files.
good luck.
Advance Wars: Dual Strike
Tetris DS
Civilization Revolution
Ultimate Mortal Kombat
Final Fantasy Tactics A2: Grimoire of the Rift
Space Invaders Extreme
Metal Slug 7
Yeah i had the same problem, I had to manually input the Civ codes in the 7-09-08 USRCHEAT.dat file before it'd even work.
After i did that everything works fine now.
I ordered an DSTT from them on June-6, and i'm still waiting for the shipment. It said the item was on backorder a couple days ago. Hopefully they send it out soon.