with saving problems the answer is to change the nds save format
play the game with FLASH 512Kbytes format and save if it comes up with a error then play the game with FLASH 32Kbytes format and if those two formats dont work then play the game and save with the other format settings
[also i would recommend using the windows magnifier when playing nds games because the screen cant be resized and the magnifier zooms in making it easy to see the emulator screen]
My Nds emulator settings are:
--Emulator speed LCD refresh--
Unlimited MHz disaster 10% - i configure this regually depending on the game
--Video Output--
24bit output or higher
--3d rendering (new version only)--
opengl or nocash
--GBA Mode--
VGA [Poppy bright]
--GBA Cartridge Backup Media--
Auto
--NDS Cartridge Backup Media--
Depends on the game - Configure this until you find one that works
--Solar Sensor Level--
Bright Sunlight
--Sound output Mode--
Turn this off except if you using realtime,auto emulator speed LCD refresh
also if your playing pokemon diamond and pearl then you have to have the sound playing because the game will freeze if no sound is playing (so you could just turn the speakers volume down or set it to realtime auto)
--Sound Desire Sample Rate--
High [44khz] [best]
--Multiboot Normal/BurstDelays--
Medium/Medium [Stable]
--Number of Emulated Gameboys--
1 (never st this to more than one when playing nds games because the emulator crash)
--Link Gamepacks--
Gamepacks in all GBA's