Image data corrupted with 10.6.2 install.

Get the Combo updater instead and re-apply:

http://support.apple.com/kb/DL959

Try downloading after installing Firefox 3.5.5 if not already doing so. I've only seen your problem where users are running Safari.

Edit: Actually, [go here|http://discussions.apple.com/thread.jspa?threadID=2237531&tstart=0]. I made the same recommendation on the linked thread, but it apparently did not work. Still, I would try FF.

Message was edited by: donv (The Ghost)

The most likely two cause of the corruption are:

1. Your OS has one or more damaged files used in the downloading or mounting of disk image files. Solution: reinstall the OS from the original DVD.

2. Your hard drive's file system has corruption problems. Solution: use Disk Utility's "repair disk" function to correct this.

Note that in either case, you will have to download any corrupted disk image files again, once the problem has been eliminated.

Try what R C-R says. If no joy, and you haven't already tried it, then Do a repair install of Sno by installing Sno over Sno as in an upgrade install. Such an install, while usually very safe, still is an install so be appropriated backed up if you proceed. You will need to reinstall the 10.6.2 combo updater.

I would not do any sort of install unless I had an external drive with a bootable clone of my internal-drive boot volume on it. I think that there is enough risk in installing that such conservatism is warranted. I would not use time machine for an installation backup; I don't trust it enough.

If you do not get a good install, then you can restore your internal back to where you started using the clone, and nothing will be lost. In doing a repair install, the clone is your data backup and fail-safe device. You can clone with Disk Utility, SuperDuper, or Carbon Copy Cloner. If you like the idea of cloning for a backup, etc., then I would acquire one of the last two mentioned programs.

To clone using Disk Utility (DU)

1. Start DU;
2. Make sure you external drive is partitioned GUID;
3. Choose Restore;
4. Drag your internal volume to the source box;
5. Drag your external partition to the destination box;
6. Choose Erase Destination; and
7. Click restore.

It will take an hour more or less. Once the clone is made, start up from it to make sure it is functional.

Interesting, I have the same problem no matter what .dmg files I download.

The problem is independent of how I download them: Firefox, Opera and Safari have the problem as well as receiving a file through Adium (chat client, ICQ protocol).

I get different checksums (using md5) every time I download a file (for instance, downloading iPhoto Library Manager thee times gives me three different checksums).

The problem does not apply to other file formats (.tar.gz etc).

Doing a safe boot got rid of the problem (while running the safely booted system), but booting normally makes the behavior come back.

I don't know what else to try. Anyone have a hint?