The only program I've found it to conflict with is Spybot S&D's realtime scanner. It seems to do OK with AVG8 too, but is duplication. I still use it on W98-AVG7.5-SB protected systems.
Other free tools for detecting spyware I use are Superantispyware, Spybot Search and destroy, and HiJackthis. No one product can find all the crap that seeks to reside on your computer.
Yes, I said that in my post... However, if you do an update, I think that you might be surprised at the date of the last update.
Mark