ok lads here's a heads up for you on that problem
ok sloved it and you will not belive this it was a texture's name stopping the exporter from working
it must be hard wired in to the code not to let any textures with the word weapon in it to export

??
after changing the name of the texture it then exported ok i removed the weapon from the texture name and replaced it !!
the other thing i have spotted there was a screen shot of exported models doing strange things like all the animated parts grouped in the centre and the model being al black , for me i had forgotten to ad a new texture in the texture file so when testing it came up like that aftwer adding the new texture to the texture file hay pressto the model was ok and working fine

?????? ( god knows why the textures can have that effect on the mdl ) so if you see that in the preview aircraft viewer check your texture file
regards ed