The Tuttle entry for 别 (single character) does not include its traditional form, 別. This error does not occur in compounds.
The three Guifan entries for 别 (bié) also does not include its traditional form, 別. The entry for 别 (biè) has 別 but should also include 彆 as well.
ACE, Guifan, and Adsotrans lists the traditional form of 别扭 as 別扭, while Oxford and CEDICT lists it as 彆扭, and ABC lists both. Perhaps both traditional forms should be included in all dictionaries?