If you have a Mac Pro system and have updated to Apple's recently released OS X 10.7.4 update, you may find an apparent warning window appear whenever you reboot your system. The warning looks like a standard information dialog box window that contains a picture of a Mac Pro system from the side, but the rest of the window contains no information of value.
Instead of a hint at what the warning could be about, the window simply states "keyApplicationTitle" in the area where the referenced application name might be, "keyWarningOptimalInfo" where the information or warning description text might be, and instead of an OK button the only button in the window contains the text "keyOKButton."
These components are clearly the code structure that Apple uses to insert the appropriate text strings into the window, but it appears either a syntax error or some similar oversight has caused the string association to misfire, and instead put the object titles into the window. Clicking the OK button seems to close the window with no apparent change to the system; however, the intent of the warning is lost to those who are experiencing it.
This error is reminiscent of the one that, where users were finding interface elements being replaced with odd green and pink patterns, with red question marks and orange "CUI" text. While not as widespread as the one in OS X 10.7.3, this one evokes similar confusion in its that users cannot figure out what their systems are trying to tell them.
Simple tests like booting to Safe Mode show no change in the behavior of this error, so those who experience it can either tolerate it or try reinstalling the OS X 10.7.4 Combo update, and perform simple maintenance procedures like running a permissions fix on the boot drive, or at the very worst reinstalling OS X followed by again applying the combo updater, though these steps are not guaranteed to work.
Hopefully Apple will clarify the situation soon, but until then Mac Pro users with this issue may have to dismiss the bizarre warning window every time they boot their systems.
UPDATE (May 13): This issue has been found to be from Apple's Memory Slot Utility, which informs users of changes to their memory configurations. This message is apparently from the utility attempting to notify the user that everything it ok, but a bug in it has prevented the message from showing properly. To fix this issue, move the program out of the /System/Library/CoreServices/ folder.