After a complete reformat and reinstall of OS 9.2.2, it still won't launch Stuffit Expander (type 3 error.. save work & restart) and it won't let me open some system files like "Late Breaking News.." aka Mac Help.
(Also, sometimes when it goes to shut down.. it gives me a bomb error "Finder".. error type 7?

Click to expand...

If the HDD allowed a reformat and re-install, that leaves RAM (simplest to isolate by removing from under the keyboard) OR the soldered RAM on the logic board could be faulty which may not get accessed until all of the RAM is utilised...

First though; the disc that was used to install Mac OS - does it have any scratches, does it need a clean, is the disc a retail version of Mac OS 9x, did you update from a version earlier than Mac OS 9.22?

Secondly: are these errors only occurring with just the default Mac OS 9 extensions and control panels?

Thirdly: have you tried an earlier version of Mac OS 9 (9.0.4, 9.1, 9.2.1)?

There is KB article on apple.com re: Type 1, Type 2, and Type 3 System Errors

http://support.apple.com/kb/TA21578?viewlocale=en_US

Here is a table from apple.com, re: System Error Codes: 1 to 32767

http://support.apple.com/kb/HT2088?viewlocale=en_US

(Many are fairly cryptic)