Adobe has removed this update because of several bugs discovered after the release. Adobe suggests removing Lightroom version 1.4 and reinstalling version 1.3.1 until such time as the fixes are published.
Adobe’s Lightroom Journal has all the details for the problems with this update as well as instructions on getting back to version 1.3.1.
If you still have your 1.3.1 update which contains the entire program, then do the following to uninstall Lightroom 1.4 based on your operating system:
Mac: Delete the Lightroom application in the Application folder(Mac) and Delete the following file: Library/Receipts/Adobe Photoshop Lightroom.pkg
Windows: Choose the Uninstall Lightroom 1.4 menu item from the Windows start menu. The Add/Remove Program utility on Windows will also achieve the same result.
After I perform the uninstall and reinstall (windows), I’ll let you know if there are any lost presets or problems. I would recommend a backup of all your user settings and your catalog prior to any updates or changes to your program.
The macintosh update is here.
According to Adobe this update adds support for more RAW formats and updates printer compatibility with Mac OS (Leapord):
The Adobe® Photoshop® Lightroom® 1.4 update includes these enhancements:
• Additional camera support for the Canon EOS 450D (Digital Rebel XSi/EOS Kiss X2), Nikon D60, Sony A350, and more
• Updated printer driver compatibility for Mac OS X v10.5 (Leopard)