#297 X64 directive and OMF output

[MazeGen]

File with the following contents assembled with "jwasm -c" generates OMF .obj file:

.X64
.MODEL FLAT
END

I never used OMF files but it suprised me that it is possible to assemble to OMF file from 64-bit source file. However, when I load the .obj file to IDA 6.4, it interprets it as a 32-bit file. Does jwasm generate the OMF file correctly? Is 64-bit OMF output actually supported? Shouldn't jwasm return an error or always assemble 64-bit files to COFF unless specified otherwise?