The second morph my not be working because simply mirroring the morph creates a left hand I don't think it puts it in the exact same place spacially. The reason morphs don't work in programs like Amorphium is because the program doesn't have the same space relationship as poser. (I worded that rather strangley but I hope you get the idea.) My guess is that whatever program you are using is placing the mirrored hand in a slightley different space compared to poser try importing a left hand from your origanal poser obj and then place your new mirrored hand in that exact position. Don't know if this is the answer but it's worth trying.