Thanks for the screen.Here is an example of the missing textures:
http://i.imgur.com/lnf2y.jpg
Here is my display config: http://i.imgur.com/bksFD.jpg
I'm running an Nvidia 9800 GT which is a bit of an older card.
I'm gonna try something with the texture to make it more lite kind of so your graphic card can take it.
I was actually make 2 version of the HD pack with one using maximum size of the texture and an other using smaller size but trying to keep a good quality.
Gonna do this now and upload in 10min the lite version.
I hope its gonna work
Edit: Download the lite version here http://hevon.saintsrowmods.com/Hevon HD Texture pack Lite version.rar