Using a desktop pattern on the Find File utility does use a bigger portion of Find File's available memory. To workaround this, increase the memory for the Find File utility because it is actually an application.
To increase the memory for Find File:
1. Make sure you have Quit the Find File utility.
2. Open the Apple Menu Items folder in the System Folder.
3. Highlight the Find File utility and select Get Info from the File menu.
4. Increase the Preferred memory size to 560.
5. Close the Find File Info window.