Software Update -- iTunes Problem


I have a problem with the software updater in OS X (10.4.2), normally it works fine, apart from when it comes to updating iTunes. The last two iTunes updates (5.0.0 and 5.0.1) have caused the auto software updater to stall on 'Install iTunes'. Last time this happened I just went to the apple website and downloaded the iTunes package but it is annoying as the auto updater should work but it doesn't. Works fine normally. Does anyone know what could be causing this problem (and no, I do not run iTunes normally it is rarely open).