CreateNode Prob

Everytime i try to replace a node using the “createnode” -node, this works in a strange way: I get the node replaced, but the window of the new node, that opens, is flickernig with a certain period. Its flickering makes changing the path (in the first pin)in the create node impossible, and other actions in other windows seem to be frozen as long as it flickers (Seems to put back actions to zero before they effect with every flicker).
The only way for me to break this state is to close the new window, which causes my node to be removed from my root. Is it a bug in my installation? Is it my system, or is it something i didn’t got right yet?