S3 randomly giving me "BadDigest" errors

I have a node.js app that periodically pushes some data to Amazon S3. I'm using a Put request to push a buffer over to S3.

I know that the "content-md5" parameter of the S3 request needs to be the base64 encoded Md5 hash of the content that I'm pushing. What has me confused is that 90% of the time, my requests succeed. The other 10% of the time, without my hashing method changing at all, Amazon gives me back "badDigest" error: 

{ [Error: API error with HTTP Code: 400]
  headers: 
   { 
     'content-type': 'application/xml',
     'transfer-encoding': 'chunked',
     date: 'Fri, 06 Apr 2012 02:20:14 GMT',
     connection: 'close',
     server: 'AmazonS3' },
  code: 400,
  document: 
   { Code: 'BadDigest',
     Message: 'The Content-MD5 you specified did not match what we received.',
     ExpectedDigest: 'fPRrmxapcSHmI2gljme1Fg==',
     CalculatedDigest: 'w6PoDxh2ty478+Mw2UwTrA==',
     RequestId: '1018E7A80A8B0B00',
     HostId: 'W/SK/OovQHlsi593DJ154pkHdOrUk3oMWmIGNdOKj3WaHa8cBknhB+7H5IdZLUjt' } }

Has anyone else experienced this randomness from S3 before? Am I missing something obvious?

Thanks!

You likely forgot to specify 'utf8' as parameter for update.

var status = 'काक्नोम्यत्क्नोम्यत्चं शक्नोम्यत्तुमतुम् ।तुम् ।् । नोपहिनस्ति माम् ॥';
var contentMd5 = crypto
                  .createHash('md5')
                  .update(status, 'utf8')
                  .digest('base64');

Without it works in the most cases but not when your string includes multibyte characters.