I did a LOT of research on the glitches on Majesco's website before getting the game for myself and I can give you two tips that will help you avoid the biggest glitches that can basically brick the game card:
1. Don't use the "save and quit" option. If you want to save and quit, use the "save" option, and then manually turn the DS off at the switch.
2. When you create your profile make sure your name has four or more letters. Three or less can crash your game. (Example: "Al" could crash it. "Alex" will not.)
I've been playing it for hours now, and haven't had any problems, although I hear there are a few smaller glitches here and there. I love the game, and I recommend it, although not all gamers will appreciate the extremely long campaigns. These missions can take as long as three hours to complete. Fortunately, don't have to commit to a three-hour play session because you can save at any time, so you can jump in and out whenever you want.
Just remember: don't "save and quit", and don't use a name that's less than four letters.