some of my textures are invisible

[helpmeplease]

I just bought the orange box, loaded up half life 2 and as i ride that train in the roof and the floor of the train are invisible. As i get out and walk around the ground about 5 feet in all directions of me becomes either white, invisible, or a jumbled mess of frames

Any suggestions would be handy, thanks

 

[AciD]

Have you tried Verifying GCF Cache Files?

 

[helpmeplease]

hey thanks, i just tried that but the problem still persists, are there any other suggestions?

 

[AciD]

Are you using 64bit version of Source?