Michel,
Yes, please log it. This sounds like it may already be logged though because it founds familiar to me. Support will sort out the tickets but the more people we have asking for a particular fix will prioritize it higher.
Maybe adjust your CTs to bring down a blank or -NONE- value as a temporary measure to get around this bug and forget about special value for now. Then you could just set the initial value in the transaction and it will default to the empty row.
Jason Latko - Senior Product Developer at SAP