A few users have written about (apparent) anomalies when using QRecall with Leopard's Spaces feature. This affects the appearance and placement of the QRecall Activity window.

The problem is that QRecall Activity window belongs to a hidden application named QRecallMonitor. As such, the QRecall Activity window will appear in whatever space was active when the monitor started (typically when you log in). Opening the activity window from the QRecall application or by starting an action may switch spaces. This can be disconcerting, to say the least.

To fix this:
• Open the Spaces panel in the System Preferences
• Click the plus button to to add a new application assignment
• In the open dialog, press Command+Shift+G to get the "Go to" panel
• Type, or paste in, the path "/Applications/QRecall.app/Contents/Resources" (without the quotes). If your QRecall application is someplace other than the /Applications folder, change that portion of the path as necessary.
• Click the Go button
• In the Resources folder, scroll down and select the QRecallMonitor application
• Click the Add button
• Find QRecallMonitor in the Application Assignments list and change its Space assignment to "Every Space"
• Log out and log back in

The QRecall Activity window will now appear consistently in all spaces.

An update:

The latest version of QRecall will force the Activity window into all spaces. This can now be turned off using the QRMonitorSpacesJoinAll expert setting.

See the Advanced QRecall Settings thread for the details.