RQMExcelWordImport-Tool does not upload excel content for attribute with type MEDIUM_STRING / how to solve?

Hi!
We encounter problems uploading excel test cases into RQM/ETM when using tc attributes of type MEDIUM_STRING as follows:
==> behavior: excel add-in
- shows no errors,
- test case and other attributes are uploaded correctly
- but content of MEDIUM_STRING attribute is not uploaded
Upload in general works fine for testcases, testplans, requirement links
What is going wrong? Did someone encounter same problems with MEDIUM_STRING attributes?
Please help, thanks!
Tried:
- RQM 6.0.6.1 iFix018 & ETM-Extras-ETMExcelWordImporter-7.0.2 (ETMExcelImporterSetupForDotNET45.msi)
- ETM 7.0.2 iFix005 & RQM-Extras-RQMExcelWordImporter-6.0.6.1 (ETMExcelImporterSetupForDotNET45.msi)
Example config file:
--------------------
// test cases
testcase.XLSWorksheetID="Upload"
testcase.XLSStartRow=2
testcase.XLSDelimeter=\n
testcase.XLSArtifactID=A
testcase.dc:title=B
testcase.dc:description=B
// the following does not work for MEDIUM_STRING. (default small string working). Value of attribute in Q1 (column name, e.g. "TestMediumAttrib")
testcase.customAttributes identifier=Q1.name=Q1.value=Q.type="MEDIUM_STRING"