Especially if your applications' custom icons have reverted to generic icons, MacMan is likely to have nailed the cause of the confusion. You can begin to hold down command-option when the splash screen appears—which will spare you some finger-fatigue—and hold them down until a panel asks "Do you rilly rilly rilly wish to rebuild ... ". All attached hard drives (one or more, if you have externals connected and active) will have their desktops rebuilt. There are commercial utilities that do a better job than Apple's, but monthly (say) rebuilds are a worthwhile addition to your normal housekeeping, and whenever applications and their files lose sight of each other. The Desktop files are constantly being rewritten during normal use of your computer, and can quickly become bloated with the shadows of deleted files, scrambled at scattered locations, and so on.

Norton versions after 3.2 were neither HFS+ aware nor PPC-fluent, which you may already have found out. DiskWarrior 2.1.x and its travelling-mate PlusOptimizer, by contrast, do a reliable job of disk directory defragmentation and file defragmentation and optimization, respectively. Unfortunately, it is likely to be available only second-hand now. Perhaps you can find someone who is leaving OS 7.6.1 - OS 9 behind in their move to OS X.

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