I tried to mount a bucket that is in the us-west-2 AWS region, but I get this error message:
The operation couldn’t be completed. (The authorization header is malformed; the region 'us-east-1' is wrong; expecting 'us-west-2' error -1.)
That suggests that the Cloud Mounter software is assuming the us-east-1 region. Seems like a bug; if the URL configured for the drive is h t t p s : / / s3.us-west-2.amazonaws.com then the Cloud Mounter should specify the us-west-2 region when making the connection. Maybe you need another field (a region field) in the Amazon S3 connection configuration dialog.