The Collaborative International Dictionary of English v.0.48:

Problematic \Prob`lem*at"ic\, Problematical \Prob`lem*at"ic*al\,
   a. [L. problematicus, Gr. ?: cf. F. probl['e]matique.]
   1. Having the nature of a problem; not shown in fact;
      questionable; uncertain; unsettled; doubtful; as, his
      theory is problematic because it fails to explain several
      facts. -- Prob`lem*at"ic*al*ly, adv.
      [1913 Webster]

            Diligent inquiries into remote and problematical
            guilt leave a gate wide open to . . . informers.
                                                  --Swift.
      [1913 Webster]

   2. Having characteristics which will create difficulties or
      undesirable consequences; -- of a proposed action; as, the
      proposed law is problematic because it will cause many
      people to lose their jobs.
      [PJC]

WordNet (r) 3.0 (2006):

problematically
    adv 1: in such a way as to pose a problem