Problems with Pyramids and 'Mosaic to new raster'

Hi everybody,

I want to mosaic about 20 raster datasets to one new raster dataset. Everything works fine so far, but only the visualization of the output is for some zoom level incomplete.
When I zoom in the areas with incomplete visualization become visualized, so I suggested that this a problems with the build pyramids.

Therefore I tried two different steps:

• deleting all existing pyramids of the rasters to be mosaiced

• calculating the same pyramid level for all input rasters mosaiced

None of these attemps solved my problem! Do you have any ideas?

Thanks in advance,
jo