can't play songs in iTunes

[kitcat11848]

I seem to be having similar problems as others recently have posted. i download my songs, they appear in my list under M Music but i cannot get them to play. This started just before Christmas. The only thing new to my computer is SP3 but I think I have done successful downloads that play since installing SP3. I did doublecheck some of the attempts today and the files appear to be on the virus/spam list according to KB/song. What's up with all the virus/spam on LW? I have XP 2002 with SP3, Intel Quad4 2.40 ghz, 4G Ram, Linksys router WRT 300N, LW 4.18.8, Java 1.5.0_06, McAfee but no firewalls except thru router. Everything use to work before Christmas but now I get spam sites plkus downloads don't play. What gives?