it an but u have to edit the file - its really easy though

in maya 7 save the files in asci format .ma instead of binary .mb

ok now open this in something like wordpad or note pad but wordpad isbetter as it breaks the lines

now in the first few lines where it says maya 7.0 change to maya 6.0 (6.0 as 6.5 will open these files) it may say requires maya X.X but change to 6.0 and save it

then open in maya 6.5 and it should work fine

if u get stuck ask for more help here