HS 2237+8154: On the onset of mass transfer or entering the period gap? B. T. Gänsicke, S. Araujo-Betancor, H.-J. Hagen, E. T. Harlaftis, S. Kitsionas, S. Dreizler and D. Engels A&A, 418 1 (2004) 265-270 Published online: 02 April 2004 DOI: 10.1051/0004-6361:20035591