JMeter 2.10 send SOAP requst gives unmarshalling error on server unable to support special unicode german carecter

To test web service I am using JMeter 2.10  with OSB (Oracle Service Bus), testing worked fine, but when we tried to send some special characters like 'ÖÜÄ' etc in XML data of  SOAP request I found that OSB was not able to parse it.  after several checks I also checked that when sending soap request XML has  UTF-8 encoding

xml request look like

&lts:envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"&gt
 &lts:header&gt
  .... some header
 &lt/s:header&gt
 &lts:body&gt
  &ltnameapp&gtsome special charecters Üäöü here &lt/nameapp&gt
&lt/s:body&gt&lt/s:envelope&gt

when i took a look at raw http header information of request it looks like in Jmeter as follows

Request Headers:
Connection: keep-alive
Content-Type: text/xml; charset=utf-8
dynaTrace: PC=JMETER;NA=Soap Request (INA, Small Input - Small Output);VU=Client 10
Content-Length: 2220
Host: bac.edf.to.do:24001
User-Agent: Apache-HttpClient/4.2.6 (java 1.5)

after lot of R AND D I found that when in above raw request it uses http sampler implementation of HttpClient/4.2.6 so i change in JMeter http sampler implementation from HttpClient/4.2.6 to HttpClient/3.1 and request worked.

Well I need to investigate further may be a bug in current version of apache HttpClient or Jmeter , but this was the solution to my current problem. hope this helps to you as well.