I figured it out.
i'm getting stuff onto my letcool from a mac, and for some reason when i copy a rom over it also creates a duplicate file that doesn't work. these duplicate files are invisible on my mac and even on my PC, but for some reason the Letcool lists them along side the roms. i was unknowingly trying to run these duplicate files when i got the white screen.
i had a similar issue with a Archos mp3 player i had a few years back. just a mac -> PC device issue i guess.