CSV parse issue on EC2 instance when using Executrix

I am using this gem to perform a bulk query from Salesforce and than doing a bulk update to Salesforce. However often this gem start throwing this error : 

CSV::MalformedCSVError: Illegal quoting in line 1.
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1925:in `block (2 levels) in shift'
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1887:in `each'
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1887:in `block in shift'
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1849:in `loop'
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1849:in `shift'
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1791:in `each'
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1805:in `to_a'
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1805:in `read'
	from /usr/local/rubies/1.9.3-p327/lib/ruby/1.9.1/csv.rb:1379:in `parse'
	from /mnt/sendengine-production/shared/bundle/ruby/1.9.1/gems/executrix-1.0.0/lib/executrix/http.rb:72:in `process_csv_response'


After sometime this error gets resolved itself and everything starts to work smoothly. What can be possible reason behind this ?

The Rails application is hosted on Amazon EC2 with c1.medium instance.