Why does bridge constantly re-create previews?

Question

My understanding is that Bridge generates previews and stores them in the cache.  However, it seems to forget it created the previews when I shut down then boot up the next day, so directories that I visited the day before still get the "XXX preview extractions" notice down in the bottom left and the interface is sluggish while that is going on.
I have tried purging the cache, compacting the cache, and putting the cache size on maximum.  Bridge still constantly generates previews for items that should already be in the cache.  I have "Keep 100% Previews in Cache" checked, so it shouldn't be doing that, correct?
How do I fix this problem?  It makes Bridge even more sluggish than it already is...
Thanks,
rgames

Answer 1

Definitely seeing this myself. Not sure what process is doing it, but it would have to be changing the IDs of each item in Launchpad on each relaunch of the "Dock" process (since the whole thing is controlled by an SQL Lite database in your ~/Library/Application Support/Dock folder). It could be looking at the last "something'd" date and ordering them based on that.
Crazy idea, maybe try write-protecting that database after everything is as you'd want it? Trouble is, next time you download or install an app that Launchpad would want to add, you'd need to un-write-protect it, add the app, then re-write-protect it. Scriptable, sure, but not "It just works". And even then it might not like the database not being modifyable and just crash or act oddly.
I haven't given it much effort as my primary app launch method is still Spotlight. If you want your apps to stay in order, just drag your Applications folder back to your dock and use it just like you did in [Snow] Leopard, as they'll stay in the sort order you set it there. Or submit a bug report (http://www.apple.com/feedback/macosx.html) and hope they fix it in a future release. Finally, for those who want to use Launchpad and fix it themselves, may I suggest this:
Get your apps in the order you want them
Back up the database in ~/Library/Application\ Support/Dock to somewhere
Write a simple bash or Apple script that kills the Dock, copies that archived database where everything is in the correct order to its "live" location, then restarts the Dock
Set said script to run on boot by adding it to your Startup Items (Accounts in System Preferences)
Profit?
Of course, anytime you make an edit to what's in Launchpad or the order of Launchpad, you'd need to remember to re-backup your database so this script wouldn't overwrite your edits the next time you rebooted.
*The above idea has not been tested and merely should work given that Mac OS is nearly UNIX and as such usually behaves rationally