“no input file specified” after 2.8 upgrade

hi all,

i just upgraded to 2.8 and now i’m getting a “no input file specified” message whenever i try to log in through my admin panel (which appears as unformatted by the way).

does anyone have any clues how i can resolve this in a “dumbed-down” way? i’ve tried reinstalling the WP 2.8 upgrade (while not replacing the wp-content folder.

thanks in advance!