Try double checking the spelling.
I havn't used 3Dsmax, But I know from teh XSI mod tool that the spelling is VERY sensitive.
One thing you can do, is After placing the hardpoints and converting to .mesh format. Leave the .mesh in text, open it up in a text editor, then change the hardpoint names by hand.
It is pretty obvious how the mesh file is set up, I'm sure you'll figure it out.
It is obvious that english is not your first langege, so spelling correctly will be especialy difficult for you. (I Only know english, and I can still barley spell correctly). I sugest you double check the spelling (against the modding documentation) a couple times.
Just my sugestions, hope they help!
Also, those are NICE looking models.