Hello, I have OS 10.5.8 on my Intel iMac. The problem started out every time I attempted to open a particular picture (JPEG file) in Preview, the application hangs. The file would open, display, and then I'd get the rainbow cursor. The same thing happened when I tried to open up a 2-page PDF file. The first page displayed, but the application hung for about 1-2 minutes before I could display the second page. Some things that might be relevant: I used the Disk Utility to Verify the disk. No problems were found. I also used the Disk Utility to Verify Permissions. It found some issues, and I chose to Repair Disk Permissions. Upon completion, I rebooted and the problem persists. Force Quitting the application takes a few seconds for the window to disappear and takes nearly 30 sec. for the Preview entry to disappear from the list in the Force Quit window. I don't get the problem if I open up a Browser window, print the page, and choose the PDF | Open PDF in Preview option. To further troubleshoot, I tested opening some other picture files. They opened successfully, and I could navigate through them. As a further test, I opened up the original picture file that caused the problem in Photoshop and saved it under a new name. When I opened the new file in Preview, it did not cause any hangup leading me to conclude that perhaps the original file was corrupt. Neither did the 2-page PDF. As a final test, I opened up the original file that caused the problem in the first place. Surprisingly, this time Preview did not hang. While the problem appears to be resolved, I'm a bit concerned because this has never happened before. Also the machine had not been in use for almost two weeks. This is my main production machine. Do I need to be concerned? I appreciate any feedback. Thanks, --TMK.