After typing the word to search, and identified the result in the dropdown list, after selecting the item with tab, just before pressing return the list is refreshed and the selection changes. It is very easy to select something unwanted with a similar name, unless waiting long time for the list to stabilize before scrolling it.

Reproducible: Sometimes

Steps to Reproduce:
1. Type something in KRunner, better if ambiguous
2. Quickly identify and select the item with tab, or even mouseclick
3. Press return or click

Actual Results:  
Often the list updates itself just before the selection, ending up with something unwanted or again the highlight of the top item

Expected Results:  
A longer update delay, a freeze of the list order or item selected position, or any other more user-friendly behavior