Hrmm......i never realized it either. I have Duracells 2650s and generally use about 2-3 diff sets on a regular basis, of which last me about a few days to a week of use or maybe ATMOST 3-5 hours depending on my overclocking uses.
But yeah, I popped in a fresh old set of 2400s the other day, and it just went straight to rainbow screen.....i figured it was the age of the 2400s.....i mean i did use them for quite a while, I just figured maybe they just don't retain the charge as they used too. Although I haven't tossed them yet.....
I will re-charge the 2400s, and test them in something else. If they work, and work well....maybe it is my gp2x trying to pull too much at a time that these 2400s can't hold anymore....
We shall see.....
DSR