IMPORTANT: 

* Do NOT use Expdp/Impdp when going to (AL32)UTF8 or a other multibyte 
  characterset on ALL 10g versions lower then 10.2.0.4 (including 10.1.0.5).
  Also 11.1.0.6 is affected.

  It will provoke data corruption unless you applied Patch 5874989 on the 
  impdp side, this is caused by the impdp Bug 5874989. Expdp is not affected.

  The "old" exp/imp work fine. This problem is fixed in the 
  10.2.0.4 and 11.1.0.7 patch set.

  All existing patches for this bug are found here: 
  http://updates.oracle.com/download/5874989.html

  For 10.1.0.5 and 11.1.0.6 you can ask a backport for Bug 5874989 
  if there is not yet a patch for your version/platform.