Build 5.4.0.356 (and 6.x)
On the SOAP BizComp, the xa:message_charset (if the attribute is not included) appears to default to ISO-8859-1, instead of UTF-8 as stated in the documentation. The user has to manually add xa:message_charset="UTF-8" in order for messages to be sent correctly to most web services; this should be the default.
This should be checked for the HTTP BizComp as well.