HTTP encoding error

Environment:
We are running a mixed wM IS environment - very old: 4.6 SP3 and very new 6.5.2. The 6.5 environment isn’t yet production.

Problem:
Some international data coming into our 4.6 wM IS server contains extended characters like a-acute, e-acute, tilde etc. The transaction is sent via HTTP POST to the standard WmTN service: /invoke/wm.tn/receive

  • the 4.6 wM IS server garbles all the extended characters;
  • the 6.5 wM IS server correctly handles the extended characters;
    The HTTP header “Content-type: text/xml; charset=utf-8” is specified. We tried changing the charset to “iso-8859-1” with no success. wM IS 6.5 handles all correctly.

Any idea what patch or setting is missing/incorrect in our 4.6 environment?

Thanx in advance…