It seems that some users are experiencing problems with disk images.
These concerns appear to be related to some updates for Mac OS X that may not have been applied correctly.
- Repair permissions on your boot volume with Disk Utility located in: Applications / Utilities.
- Restart the computer to 'Repair Disk' through Disk Utility (NOTE: it may be necessary to boot the machine from the installation disc of Mac OS X to perform this action)
• Restart the computer again
• Eliminate files related to receipt updates from Mac OS X: These files have names beginning with MacOSXUpd10.xxxxxxxxxx.pkg') and are located in: Macintosh HD / Library / Receipts
• Apply the latest Mac OS X System combo update. It can be downloaded from the Apple site from this page: