10.6? 10.8? Really?? Do you have a time machine or something? 
I know you really mean 10.2.6 and 10.2.8, I'm just teasing you.  But seriously, you might need to start over from scratch and do a clean install of OS X, or at least an Archive and Install, and use the combo updater to bring it up to 10.2.8; neither option is desirable (though the Archive and Install option is more doable), but it might be necessary unless someone else has a better suggestion.
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System:
• 2.5 GHz MacBook Pro Core 2 Duo, 4 GB RAM, 200 GB hard drive, runs 10.5.6
• 1.6 GHz iMac G5, 1.5 GB RAM, 250 GB hard drive, runs 10.4.11 (slightly out of commission at this time)
• iPhone, 4 GB, OS X 2.2.1 |