Right, the reason your textures aren't loading, is because you have put some sort of mod into your game. High poly mods, will cause the textures to load slower, and occasionally not at all. The only way to fix this is to download the following:
Click Here!Mirror Courtesy of iRadio
Now, you have to extract each file into your main GTA San Andreas directory, clicking "yes, replace file" when it asks you, This .rar contains a readme in english and russian should you need any more help.
-Requesting this gets linked in the "useful topics post"
-Thanks to [ACSD]Bobby_Duke for showing me this.
-Fix created by Alexander Koryakin
http://Alexander.SannyBuilder.com