I've had a few scares recently, few freezes with my pokemon platinum (200 hrs played)
Its only happened at a few specific sections in the game, parts where snow falling like around mt. coronet and recently when I first got into the distortion world. Worried me at the time cause I thought maybe it was AP or a corrupted save (Have not had freezing in other games or I'd assume it was a contact issue). I managed to get past problematic parts luckily (fingers crossed its doesn't happen again).
I thought I'd try something and plugged my DS into the power socket, it seemed to improve things, the game didn't freeze again at the problematic areas and I was able to play through them.
I wondered afterwards whether my flashcard maybe drew more power than expected from a retail game and that this could cause random freezes or instability with some games. I'm not experienced enough but it was a logical explanation that maybe with a steady supply this could provide better stability. I found certain Rom dumping applications behaved similarly and were far more reliable with the DS plugged into a power socket, this is what prompted me to try it when I had the platinum problems.
I could be totally wrong about the cause of my platinum freezing and it could be coincidence, thought I'd share this though while on topic. I am suprised that the power thing worked but am happy as heck. Suprised tbh.