Power saving mode not working for SuperCard

My journey continues with my NIntendo DS and Nintendog. I figured out this morning something about Power Saving mode. As you may already know, closing the cover of Nintendo DS will render the NDS into power saving mode, which the screen will be turned off.

Such mode worked great on original DS game software like Nintendog. In fact, as a test, I turned on Nintendog this morning at around 9:00 am, played a few minutes and then close the cover. It's now 1:06 pm, and when I opened the cover, the Nintendog was still working fine. I will continue leaving it in such power saving mode and see if it can survive until tonight.

However, it works with SuperCard only to a point. For instance, this morning I have Wario Touch loaded, and then close the cover. Within an hour, the machine turned off itself.