Recent sync issues

My S3Sync has been running fine for a few months but has recently started erroring each day, heres a selection returned by the cron that runs each morning:

/etc/cron.s3sync/s3sync.php:

S3 command failed:
put myserver/monday/dirs/_etc_valiases.tar.gz #<S3::S3Object:0xa97c668c> Content-Type application/x-gzip Content-Length 2566
With result 500 Internal Server Error
99 retries left
Broken pipe: Broken pipe
98 retries left
SSL Error: SSL_write:: bad write retry
...etc.... (works down to 0 retries left)
SSL Error: SSL_write:: bad write retry
0 retries left
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
s3sync.rb:282:in `s3TreeRecurse': undefined method `http_response' for nil:NilClass (NoMethodError)
   from s3sync.rb:329:in `s3TreeRecurse'
   from s3sync.rb:310:in `each'
   from s3sync.rb:310:in `s3TreeRecurse'
   from s3sync.rb:329:in `s3TreeRecurse'
   from s3sync.rb:310:in `each'
   from s3sync.rb:310:in `s3TreeRecurse'
   from s3sync.rb:342:in `main'
   from ./thread_generator.rb:79:in `call'
   from ./thread_generator.rb:79:in `initialize'
   from ./thread_generator.rb:76:in `new'
   from ./thread_generator.rb:76:in `initialize'
   from s3sync.rb:263:in `new'
   from s3sync.rb:263:in `main'
   from s3sync.rb:721

-----------------------------------------------------------------------------------------------------

/etc/cron.s3sync/s3sync.php:

Connection reset: Connection reset by peer
99 retries left
SSL Error: SSL_write:: bad write retry
...etc.... (works down to 0 retries left)
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
s3sync.rb:282:in `s3TreeRecurse': undefined method `http_response' for nil:NilClass (NoMethodError)
   from s3sync.rb:329:in `s3TreeRecurse'
   from s3sync.rb:310:in `each'
   from s3sync.rb:310:in `s3TreeRecurse'
   from s3sync.rb:329:in `s3TreeRecurse'
   from s3sync.rb:310:in `each'
   from s3sync.rb:310:in `s3TreeRecurse'
   from s3sync.rb:342:in `main'
   from ./thread_generator.rb:79:in `call'
   from ./thread_generator.rb:79:in `initialize'
   from ./thread_generator.rb:76:in `new'
   from ./thread_generator.rb:76:in `initialize'
   from s3sync.rb:263:in `new'
   from s3sync.rb:263:in `main'
   from s3sync.rb:721

-----------------------------------------------------------------------------------------------------

/etc/cron.s3sync/s3sync.php:

Broken pipe: Broken pipe
99 retries left
SSL Error: SSL_write:: bad write retry
...etc.... (works down to 0 retries left)
SSL Error: SSL_write:: bad write retry
0 retries left
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
Ran out of retries; operations did not complete!
s3sync.rb:282:in `s3TreeRecurse': undefined method `http_response' for nil:NilClass (NoMethodError)
   from s3sync.rb:329:in `s3TreeRecurse'
   from s3sync.rb:310:in `each'
   from s3sync.rb:310:in `s3TreeRecurse'
   from s3sync.rb:329:in `s3TreeRecurse'
   from s3sync.rb:310:in `each'
   from s3sync.rb:310:in `s3TreeRecurse'
   from s3sync.rb:342:in `main'
   from ./thread_generator.rb:79:in `call'
   from ./thread_generator.rb:79:in `initialize'
   from ./thread_generator.rb:76:in `new'
   from ./thread_generator.rb:76:in `initialize'
   from s3sync.rb:263:in `new'
   from s3sync.rb:263:in `main'
   from s3sync.rb:721

To be honest i have no idea what any of this means, would really appreciate any help / advice.

Thanks.