My wax on the ThirdParty Disk Utilities is:
NORTON Utilities has been discontinued for Mac OS X -- it is know to damage 10.x installs(search GOOGLE for current information). Norton, in particular, is notorious for hosing people's installs, though Norton is one of the most useful tools in my bag. I think the problems most people have with Norton are:
I never let Norton repair all its crazy bit, date and icon "errors."
I turn off all Norton's bells & whistles.
If Norton does hit a SUSPECT, I always Quit and try to fix it first with Apple's FirstAid.
On the other hand, Micromat's Drive10 utility recovered a lost hard drive but the patch took more than half my client's data with it. Further, Drive10 tells me my freshly ZeroWritten hard drives have serious errors!? It is safe to say Drive10 is my LastResort.
In fact, if I have an install that requires a third-party disk utility, I will run the patch, and Erase/Restore the install at my first opportunity.
These days I do not even install 3rdparty disk utilities on my working boot system harddrive because I prefer to keep them out of the soup.
I do install Norton Utilities and DiskWarrior on my Maintenance Boot Disk (an external FireWire I use to maintain various Macs). This allows me to attach my FireWire drive to a Mac, boot off my Maintenance Boot System, and run my maintenance and BackUp routines gballard.net.
I've always gotten by with Norton, but I read that DiskWarrior is the utility most preferred by the Mac gurus.
by: ©2003 G. BALLARD • www.gballard.net
Note: G. BALLARD prefers a shredding if he is wrong or unclear.