hey, mine came back.
did you re-install your OS or something?
that's what i did. basically, i installed a new SSD drive and manually migrated everything over after a fresh install, but i downloaded the latest OS combo update.
but at some point in the process (after i posted here), that functionality came back, but i'm not sure what triggered it.
from what i can remember, i moved my entire itunes database back over along with all the plists, preferences, etc.
also, i re-activated my quicktime 7 pro on my new machine. not sure which of those things made it work, because i did a lot of stuff to get my new boot volume back to the same state it was.
(i chose to do this instead of migration assistant because i wanted to do some house cleaning and not move everything over..it's kind of tedious because you have to move all kinds of secondary files over).
but i think the problem lies with QT, QT 7 pro or itunes, since that would be what is handling that play functionality more so than just the icon views...
let me know how/when your problem first started, maybe we can figure this out...because somehow mine is working again.
sorry for late reply.
No I haven't reinstalled the os x yet. Since no one offered a working solution, and because i couldn't find a solution on the net, i just gave up. I am still considering reinstalling but, first i think i should take a back up and currenly the only portable device is formatted with ntfs, i need to buy an ntfs driver to write on it. so i am procrastinating it.
I also suspecting the problem is either related with QT or iTunes but because i have no real clue, i couldn't figured out. I do not really know when the problem first appeared but, my humble guess says after a regular system update. Because I really do not tamper with settings or something like that, so It should be happened after an update.
I am experiencing this exact same annoying issue. It is ******* me off. I've been doing a ton of reserach, and it seems this problem is a lot bigger than I had originally guessed. Everyone seems to experience this problem right after a major update/system upgrade. I, myself, just installed OS X Mountain Lion. I only noticed this after about 24 hours. I have also tried the standard suggestions (rebiulding Launch Services, clearing caches, etc.). Nothing has worked. I am going to back up and attempt a reinstall. Hopefully this works…
like i said, mine came back to me.
i think it has something to do with a conflict between QT7 and QT10 (the new one).
i have old QT7 pro installed always since it has more functionality (for editing and a few other things) than the standard dumbed-down QT that comes with newer machines.
at some point when i migrated everything over, i re-installed my mpeg-2 component and QT pro registration, repaired permissions and rebooted, and at some point it came back. also, have you launched itunes since you upgraded to mt. lion? i'm still on snow leopard and it happened to me, but fixed itself.
honestly, i don't know. i'm just describing what i did when it suddenly came back (the icons in the finder).
QT 10.00 is what plays music in the preview icons i'm assuming since the play button looks like it.
don't remove QT7, i keep both on my machine. but it seemed when i put all my plists and things back into the folders, and put in my old plug-ins (all for QT7), i got it working again.
it's always a good idea to repair permissions after any software update or software install of any kind.
then reboot the computer. see if that works. also, someone earlier mentioned that the preview icons don't work unless they are sized to 64 x 64 or smaller (or bigger, can't remember, but 64 x 64 works...command-J)
YA, that all makes sense. I repaired permissions already, so that didn't work. I use perian, so maybe it's something as simple as needed to update that? It could explain plugin problems.
The 64x64 rule refers to the size that is needed for the player button I think. If the icon is too small, the player button won't show, but the preview icon should always be there.
the problem is that i can't remember what happened exactly. there was a small time period from when it didn't work and when it did work, which all i can remember doing was manually migrating my user data and plug-ins over from QT.
oh, i mentioned itunes because at the time when it wasn't working, i hadn't yet launched itunes. (i was manually migrating over tons of apps and everything, and hadn't gotten around to it).
at some point, i moved over all my user data (plists, etc.) from my old itunes between when it didn't work and when it did again.
did you do a clean install (wipe out your hard drive and install fresh copy of mountain lion), or did you upgrade??
do you have a backup/clone of your old install?
i'm assuming that mountain lion installed a newer version of itunes on there, or did you have it up to date already?
like i said, i do remember at some point moving over all my music which meant i had to move over my plists and preferences so i wouldn't have to start from scratch. that could have been the trigger that got it working. i just gave up, but then noticed a few days later it was working, so i can't pinpoint exactly what it was. but obviously it's a QT/finder problem that might be related to itunes.
good luck. post what you find out, if you get it working.
I should say that, after my last post here, I just backed up my data, and made a fresh clean install. That solved it. And I suggest not to spend your valuable time searching on google or forums, because the cause is not known, and it is just not that much a common problem. Just make a clean install and keep your sanity. It will probably be ok after clean install.