Created Unassigned: Very slow Rendering in version 4.9.2 [25711]

Hi all!

I have version MapWinGis 4.8.8 and i want update to v. 4.9.2. And i have problem:
Shape-file wich have more 10000 shapes rendering quick (any size of window) in version 4.8.8, but in v.4.9.2 render is quickly only for size window ~300x300pix (or less size), and render is very slow for full-screen mode (~1366x768).
Properties Shapefile.FastMode and Shapefile.CacheExtents don't change its value.

Hope, your understand me

```
Shapefile sf = new Shapefile();
sf.Open(path, null);

axMap1.AddLayer(sf, true);

sf.FastMode = true;
sf.CacheExtents = true;
// after it change sf.FastMode = FALSE; sf.CacheExtents = FALSE;

axMap1.Redraw();
```