LOD Settings

hi everyone - i need your help !!
in my recent project i imported treeparts from speedtree 10.0.0 - all looked good, but when i zoomed in - the leaves were changing in a strange way (close to them). So i added LOD groups (LOD0-3) in the defaultengine.ini. The first problem with the leaves was gone, but still i have a problem with the shadows (the leafcards made in speedtree are shown in the shadows…?) I played around with changing the MIN/MAXDrawDistances - setting both to 1500 was the best result in ViewPortMode - but when i hit “G” for GamingMode my parts disappear in that range - if i set both values to 0 i have the problem with the shadows… i really don’t know what to do ???
i tried several settings like:

r.ViewDistanceScale 1 10
foilage.LODDistanceScale 1 10
r.StaticMeshLODDistanceScale 1 0.0001

with no positive results - can anybody help me ?

Maybe i found a solution for the issue with the shadows - but i don’t know if this is the correct way.
Adding an entry in the DefaultEngine.ini
r.DistanceFieldShadowing=0 (instead of default value 1)
Makes the shodows look really good - and all LOD’s are working as it should…
Any other ideas fixing this problem ?
Thanks.