Known Bad Applications
 Apps that cause Quicksilver to crash
Certain applications have been seen to cause problems with Quicksilver. If you have any of the applications below installed on your system, then try uninstalling them or updating as suggested.
If you are using DefaultFolderX, please ensure that you update to the latest (4.4.7+) version to avoid crashes
On Lion 10.7.3, the /Library/Contextual Menu Items/SyncpCMPlugin.plugin causes QuickSilver to crash when trying to access any of the preferences.
To remove the plugin: make sure you have administrative privileges, then trash the two following files:
/Library/Contextual Menu Items/SCFinderPlugin.plugin /Library/Receipts/SCPlugin.pkg
 Apps that interfere with Quicksilver
This list contains a list of known applications that interfere with Quicksilver. Try disabling these applications to see if it fixes your problems
- Windowshade X
- Spirited Away (though it should work fine as long as you add a check to Quicksilver in Spirited Away's "Exclude List")
- Fruit Menu
- USMLEWorld QBank (only if the QS clipboard plugin is installed)