I'm trying to sync files between S3 buckets in two different regions (US-East-1 & US-West-2) using the following command.

s3cmd sync s3://bucket1 s3://bucket2

But it's failing with the following error.
ERROR: File s3://bucket1/File1_20130612.tgz could not be copied: 400 (InvalidRequest): The specified copy source is larger than the maximum allowable size for a copy source: 5368709120

s3cmd version 1.1.0-beta3

Does this is been fixed in latest build or is there any workaround to make this work?