Ok, this little addition to your OpenJpeg unit solves the problem:

Code:
{$ifdef unix}
  {$ifdef fpc}
    uses math;
  {$endif}
{$endif}  
...
      {$linklib libopenjpeglinx86.a}
      function pow(const base, exponent: Double): Double; cdecl;  export;
      begin
        Result:= Power(base, exponent);
      end;
I wonder if I can replace all of these required functions with wrapped Pascal equivalents and ditch that fat-ass c++ library altogether.

P.S. I removed {$LINKLIB stdc++} and it still compiles and still works. Don't tell me...