Seems
The Aviator isn't the only score disqualified from Oscar consideration. According to an article in Variety by Jon Burlingame posted on Oscarwatch:
Howard Shore's music for "The Aviator," ...[edited for length]... is one of several that have been disqualified by the Academy's music branch executive committee under Oscar rules, which are more restrictive than those of the other organizations.
Also failing to make the Oscar cut are Craig Armstrong's score for "Ray," Harry Gregson-Williams' music for "Shrek 2," James Newton Howard's score for "Collateral" and director Clint Eastwood's music for his "Million Dollar Baby." None was among the 81 films on a reminder list sent to the approximately 240 branch members for voting.
