osx lion finder problem
Maybe your issues are tied to Quicksilver instead of Lion? It does not appear that Quicksilver officially supports Lion yet (http://qsapp.com/download.php) you might try the following things to ensure that Quicksilver has the greatest opportunity for success:


Make sure you are running the latest version of Quicksilver (at time of writing that's ß60 for Snow Leopard).
Quit Quicksilver, Remove ~/Library/Caches/Quicksilver/, Restart Quicksilver
Check the FAQ for information on crashes: http://qsapp.com/wiki/FAQ#Quicksilver_crashes


If none of those work you could try uninstalling it and see if that fixes your issues. If it turns out that Quicksilver is the issue you might checkout http://alfredapp.com/ — I have no relation to the company but I have replaced Quicksilver on my machine with Alfred and would never go back.