After our initial report indicating that deleting the com.apple.quicktime.plugin.preferences.plist could alleviate some performance problems in Safari apparent after application of Security Update 2005-006.
It now appears that deletion of this particular preference file can resolve some other Safari performance issues not necessarily related to the most recent security update. In addition, the file may need to be regularly deleted at variable intervals in order to retain performance gains.
MacFixIt reader Joseph Mina, for instance, writes:
"After trashing com.apple.quicktime.plugin.preferences.plist I noticed an immediate improvement in Safari's (1.3) performance. However, a few days later sluggishness was back (spinning beachball, slow load times). Trashing this preference file again led to improved performance."
The com.apple.quicktime.plugin.preferences.plist is located in the folder ~/Library/Preferences (your user Library folder). Simply drag the file to the trash and quit, then re-launch Safari.