[NTG-context] Rotating two lines in a table

There is a bug(?) with \starttext \bTABLE \bTR \bTD[orientation=90]{first line\crlf second line}\eTD \bTD{first line\crlf second line}\eTD \eTR \eTABLE \stoptext The second cell is partially written over the first cell. How can I say: Don't do that :-) ?