EDIT: for others having comparable trouble with prop models from models/gm_forest, there's a thread here: http://forums.steampowered.com/forums/archive/index.php/t-936001.html that offers some solutions, albeit non have worked for me.

I'm quite new to using hammer, so hopefully I'm just doing something wrong or missing something.
After compiling my map from hammer and run it in L4D2, certain props seem to have their textures replaced with a silvery/white somewhat reflective texture. I figured it'd be something to do with missing cubemaps, but it also happens to some plants. Now the strangest part is, some of the plants for example have their normal textures, where others don't, even if they're using the same model.
What could be going wrong? How do I solve this? If it is actually missing cubemaps I'm going to slap myself.