iCal isn't updating w Software Update

Running OS 10.6.8, iCal 4.0.4

I happened to notice that the iCal icon in my dock said "iCal (original)", which isn't usual. Looked up latest version, then (although set to auto-check weekly) ran Software Update, but no updates identified. Then discovered iCal isn't listed as "installed software in SU prefs (OS 10.6.8 update and supplemental update done late July).

Anybody have any idea what's going on or how to get iCal included in SU? Thanks for any tips.