I would think that anything that doesn't run in the background would be 'safe', like SpyWareGuard and SpywareBlaster et al. As dlr_graph intimated above, why bother with paying for OneCare if you don't trust it, there are enough freewares out there to take care of the job in XP and I use Avast free with Vista's FW.
I currently run AVG free and PCTools firewall and ZA FW before that for XP with the above two that I mentioned and have been running this combo without any problems for the last five years. It's up to you of course, it's just my opinion.
BTW, it's never a good idea to run more than one firewall or AV, they do not mix as they interfere with each other, you have to choose one or another. In this case more is not better.
Everything that irritates us about others can lead us to an understanding of ourselves. -- Carl Jung
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