@dan013: You can read about current limitations and possible issues of specific build in
this topic (it's now also mentioned in the first post). Like said above, some textures in the game are virtual ones, which are currently not supported by umodel. As for the usage of third party tools, for example fmodel, it's better to address related to them questions to respective communities.
To all other users: If someone wants to post something useful, please do it in more sensible way (add some explanation, include link to the mentioned file or topic, etc). Otherwise it will be even more confusing for newcomers.