UTF-8 chars are not URL encoded correctly

REPRO: Create test step (mine is a REST Test Request), with UTF-8 character(s) as a parameter to the endpoint (see attached); Attempt the call;

RESULTS: UTF-8 characters aren't URL-encoded correctly:
- The pre-URL encoding value I'm using is: test-ÁÉÍÓÚÑÜáéíóúñü¿¡ºª«»€@mydomain.com
- soapUI-Pro 3.6 converts it to: test-%E7%83%EA%EE%F2%84%86%87%8E%92%97%9C%96%9F%C0%C1%BC%BB%C7%C8%DB%40mydomain.com
- When decoded from soapUI's URL encoding, the value is: test-çƒêîò„†‡Ž’—œ–ŸÀÁ¼»ÇÈÛ@mydomain.com

EXPECTED: UTF-8 characters should be URL-encoded correctly:
- The pre-URL encoding value I'm using is: test-ÁÉÍÓÚÑÜáéíóúñü¿¡ºª«»€@mydomain.com
- soapUI-Pro 3.6 should convert to: test-%C1%C9%CD%D3%DA%D1%DC%E1%E9%ED%F3%FA%F1%FC%BF%A1%BA%AA%AB%BB%80%40mydomain.com

WORK_AROUND: none (as far as I can tell)

NOTES: This defect is blocking all i18n tests