I just read "Disable your Anti Spyware Programs!" in the "HELP! Think you are Infected? forum"

What I understood was not to have to have two spyware resident programs running at the same time. Is this correct?

If so, which of these two - Spybot Teatimer or Spysweeper Shields - would be the most affective to run?
Also running on my system is Trends A/V Real Time Agent. Does this have a affect on the spyware scanners?

Any information would be much appreciated...Thanks.