Helps to get rid of low textures, is the fast camera rotation a bit from side to side or (but not 100%-camera zoom right mouse button). This started happening in the 0.62. Before 0.62 I dont have such big problems with not loading textures.
I heard that this often happens on laptops but on the PC too.
Texture quality set at high. (sorry my english is not very)
Here are just a few examples, before and after fast camera rotation from side to side:
{F70003}
{F70005}
{F70007}
{F70009}
{F70011}
{F70014}
{F70024}
{F70026}
{F70028}
{F70030}
{F70032}
{F70034}
{F70036}
{F70038}
{F70040}
{F70042}
{F70044}
{F70046}
{F70048}
{F70050}
{F70052}
{F70055}
{F70057}
{F70060}
{F70062}
{F70064}
{F70066}
{F70068}
{F70070}
{F70072}