Utilities to run on ibook

[Erin Randel]

Have any of you had problems with norton utilities, like it causing 
bigger problems? I've heard vague rumors about this, but not enough to 
base a decision.

I have a 900 ibook in need of some third-party repair utility, 
according to applecare. The persistent problems disk first aid finds 
are missing thread count and invalid volume file count.

They said I could use Diskwarrior, Drive 10 or Norton Utilities.

Macmall says they all do the same thing, small dog said diskwarrior's 
good but found they don't carry it anymore. I can get norton system 
works for about $30 with a rebate at the local wholesale club, but how 
do I find out whether it can help me?

Am i supposed to run a utility every day or week to keep my ibook 
healthy?