fixing random EXC_BAD_ACCESS with SMC/PRAM resets.

a while after I got this Mac from work, I started getting plagued with all manner of crashes. they mostly seemed to be caused by (what seemed to be) really strange low-level issues, suggested by messages warning of EXC_BAD_ACCESS, and either SIGBUS or SIGSEGV. an example crash is below, from System Preferences of all things! I have only included the first part, for brevity.

Process:         System Preferences [83284]
Path:            /Users/USER/Desktop/System Preferences.app/Contents/MacOS/System Preferences
Identifier:      com.apple.systempreferences
Version:         11.0 (11.0)
Build Info:      SystemPrefsApp-211000000000000~1
Code Type:       X86 (Native)
Parent Process:  launchd [208]

Date/Time:       2011-08-17 00:01:09.361 +0100
OS Version:      Mac OS X 10.7 (11A511)
Report Version:  9

Anonymous UUID:  5B3D93D7-29CB-4BE8-8762-265108DC7684

Crashed Thread:  4  Dispatch queue: com.apple.root.default-priority

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x00000000d0000020

the problems even persisted after my Lion upgrade. it was starting to get extremely annoying, as I was losing work and context. I tried changing the RAM, uninstalling and reinstalling as many of the offending apps as possible, all sorts. I was absolutely loath to reinstall the entire machine, as I am sure many people are, when someone at work mentioned resetting the SMC and PRAM.

being a Mac newbie, I had no idea what these were, but this tip really did the trick. so if you are experiencing random EXC_BAD_ACCESS issues affecting just about every application on your Mac, give the above resets a try.