iPod not holding its settings

I have a 60gb iPod Video. When I add a option on my menu, I hold the "Center+Menu Button" to reset it to make sure it holds. To my suprise, it does not. It goes back to what i had before I reset.
I had that problem when I reset to factory settings and then updated to the latest firmware and after an hour of playing with it, i got it to remember that i want the language in English, and then i had to charge it for 3 or 4 hours. During this time i havent touched it. Once fully charged, i added everything to the menu i wanted, reset and it all held.
I bought my wife a 30gb iPod Video, fresh out of the box, it did the same thing. So we put it on the charge for 3 or 4 hours. Again, once done, added what she wanted on the menu, reset and it all worked
Apple tells me that all i have to do is just edit what i want in the settings/extra option and thats that, no need to reset.
what i need to know is, does my ipod have to be fully charged for any editing i do to the menu to hold when i reset or do i just edit the setting/extra option and leave my ipod off for a bit.
this is peeving me off to no end not being able to get a straight answer from no one.