uv gone from my objects

[Blessern]

hey guys 

I made this object yesterday and unwrapped it in maya and textured it in Mudbox, i exported it back to maya and everything was working fine, but when i wanted to look at the grenade again today, there was nu texture on, only on the objects that has shaders on, i checked the uv map and they were gone from the objects that i had sent to Mudbox, there were still uv`s on the other stuff tho.

any one who maby has an idea how to find them again? i tryed just to auto map to see if it was all gone, but that worked. or maby how to rebuild them easily again? i tryed to export them back to mudbox and recreate uv, but nothing happend. 

/Peter L